# ets_utils
The ets_utils component provides four modules: js_api_module, js_util_module, js_sys_module, and js_concurrent_module. The following provides an introduction to these modules and describes their directory structures, APIs, and involved repositories.

# Modules
## js_api_module
### Introduction

The js_api_module provides the following classes:<br>**URL**: provides APIs to parse, construct, standardize, and encode URLs. The constructor of this class creates a **URL** object, where you can call APIs to parse and change the URL. **URLSearchParams**: provides APIs to handle URL query strings.

**URI**: provides APIs to parse URI strings.

**ConvertXml**: provides APIs to convert XML text into JavaScript objects.

**XmlSerializer**: provides APIs to generate an XML file. The constructor of this class creates an **XmlSerializer** object, where you can call the APIs to generate an XML file. **XmlPullParser**: provides APIs to parse an XML file. The constructor of this class creates an **XmlPullParser** object, where you can call the APIs to parse an XML file.

### Directory Structure

```
commonlibrary/ets_utils/js_api_module/
├── Class:URL                                                                     # URL class
│   ├── new URL(input[, base])                                                    # Used to create a URL object
│   ├── hash                                                                      # hash attribute
│   ├── host                                                                      # host attribute
│   ├── hostname                                                                  # hostname attribute
│   ├── href                                                                      # href attribute
│   ├── origin                                                                    # origin attribute
│   ├── password                                                                  # password attribute
│   ├── pathname                                                                  # pathname attribute
│   ├── port                                                                      # port attribute
│   ├── protocol                                                                  # protocol attribute
│   ├── search                                                                    # search attribute
│   ├── searchParams                                                              # searchParams attribute
│   ├── username                                                                  # username attribute
│   ├── toString()                                                                # toString method
│   └── toJSON()                                                                  # toJSON method
├── Class: URLSearchParams                                                        # URLSearchParams class
│   ├── new URLSearchParams()                                                     # Used to create a URLSearchParams object
│   ├── new URLSearchParams(string)                                               # Used to create a URLSearchParams object
│   ├── new URLSearchParams(obj)                                                  # Used to create a URLSearchParams object
│   ├── new URLSearchParams(iterable)                                             # Used to create a URLSearchParams object
│   ├── append(name, value)                                                       # append method
│   ├── delete(name)                                                              # delete method
│   ├── entries()                                                                 # entries method
│   ├── forEach(fn[, thisArg])                                                    # forEach method
│   ├── get(name)                                                                 # get method
│   ├── getAll(name)                                                              # getAll method
│   ├── has(name)                                                                 # has method
│   ├── keys()                                                                    # keys method
│   ├── set(name, value)                                                          # set method
│   ├── sort()                                                                    # sort method
│   ├── toString()                                                                # toString method
│   ├── values()                                                                  # values method
│   └── urlSearchParams[Symbol.iterator]()                                        # Used to create a URLSearchParams object
├── Class:URI                                                                     # URI class
│   ├── URI(str: string)                                                          # Used to create a URI object
│   ├── scheme                                                                    # scheme attribute
│   ├── authority                                                                 # authority attribute
│   ├── ssp                                                                       # ssp attribute
│   ├── userinfo                                                                  # userinfo attribute
│   ├── host                                                                      # host attribute
│   ├── port                                                                      # port attribute
│   ├── query                                                                     # query attribute
│   ├── fragment                                                                  # fragment attribute
│   ├── path                                                                      # path attribute
│   ├── equals(ob: Object)                                                        # equals attribute
│   ├── normalize()                                                               # normalize attribute
│   ├── checkIsAbsolute()                                                         # checkIsAbsolute attribute
│   ├── normalize()                                                               # normalize method
│   └── toString()                                                                # toString method
├── Class:ConvertXml                                                              # ConvertXml class
│   ├── ConvertXml()                                                              # Used to create a ConvertXml object
│   └── convert(xml: string, options: Object)                                     # convert method
├── Class:XmlSerializer                                                           # XmlSerializer class
│   ├── new XmlSerializer(buffer: ArrayBuffer | DataView, encoding?: string)      # Used to create an XmlSerializer object
│   ├── setAttributes(name: string, value: string)                                # setAttributes method
│   ├── addEmptyElement(name: string)                                             # addEmptyElement method
│   ├── setDeclaration()                                                          # setDeclaration method
│   ├── startElement(name: string)                                                # startElement method
│   ├── endElement()                                                              # endElement method
│   ├── setNamespace(prefix: string, namespace: string)                           # setNamespace method
│   ├── setComment(text: string)                                                  # setComment method
│   ├── setCData(text: string)                                                    # setCData method
│   ├── setText(text: string)                                                     # setText method
│   └── setDocType(text: string)                                                  # setDocType method
└── Class: XmlPullParser                                                          # XmlPullParser class
    ├── new (buffer: ArrayBuffer | DataView, encoding?: string)                   # Used to create an XmlPullParser object
    └── parse(option: ParseOptions)                                               # parse method
```

### Usage

#### Available APIs


| API| Description|
| -------- | -------- |
| URL(url: string,base?:string \| URL) | Creates a **URL** object that references a URL specified using an absolute URL string, a relative URL string, and a base URL string.|
| tostring():string | Converts the parsed URL into a string. Its function is the same as that of read-only **URL.href**.|
| toJSON():string | Converts the parsed URL into a JSON string.|
| new URLSearchParams() | No-argument constructor that creates a **URLSearchParams** object. The question mark (?) at the beginning of the query string will be ignored.|
| new URLSearchParams(string) | Constructor that creates a **URLSearchParams** object with the string type specified. The question mark (?) at the beginning of the query string will be ignored.|
| new URLSearchParams(obj) | Constructor that creates a **URLSearchParams** object with the object type specified. The question mark (?) at the beginning of the query string will be ignored.|
| new URLSearchParams(iterable) | Constructor that creates a **URLSearchParams** object with the iterable type specified. The question mark (?) at the beginning of the query string will be ignored.|
| has(name: string): boolean | Checks whether a key in this **URLSearchParams** object has a value. It returns **true** if the key has a value and returns **false** otherwise.|
| set(name: string, value string): void |  Sets the value for a key in this **URLSearchParams** object. If key-value pairs matching the specified key exist, the value of the first occurrence of the key-value pair will be changed to the specified value and other key-value pairs will be deleted. Otherwise, the key-value pair will be appended to the query string.|
| sort(): void | Sorts all key-value pairs in this **URLSearchParams** object based on the Unicode code points of the keys and returns **undefined**. |
| toString(): string | Obtains strings that can be used for URL query based on this **URLSearchParams** object.|
| keys(): iterableIterator\<string> | Obtains an iterator that contains the keys of all the key-value pairs in this **URLSearchParams** object.|
| values(): iterableIterator\<string> | Obtains an iterator that contains the values of all the key-value pairs in this **URLSearchParams** object.|
| append(name: string, value: string): void | Appends a key-value pair into this **URLSearchParams** object.|
| delete(name: string): void | Deletes key-value pairs of the specified key from this **URLSearchParams** object.|
| get(name: string): string | Obtains the value of the first key-value pair with the specified key in this **URLSearchParams** object.|
| getAll(name: string): string[] | Obtains all the key-value pairs with the specified key in this **URLSearchParams** object.|
| entries(): iterableIterator<[string, string]> | Obtains an iterator that contains all the key-value pairs of this **URLSearchParams** object.|
| forEach(): void | Traverses the key-value pairs in this **URLSearchParams** object by using a callback.|
| urlSearchParams\[Symbol.iterator]() | Obtains an ES6 iterator. Each item of the iterator is a JavaScript array, and each array contains a key and value.|
| URI​(str: string) | Constructs a URI by parsing the given input parameter according to the syntax specified in Appendix A of RFC 2396.|
| scheme​ | Obtains the scheme component of this URI; returns **null** if **scheme** is not defined.|
| authority​ | Obtains the decoded authority component of this URI; returns **null** if **authority** is not defined.|
| ssp​ |  Obtains the decoded scheme-specific component of this URI.|
| userinfo​ | Obtains the decoded userinfo component of this URI. The return value contains password and username.|
| host​ | Obtains the host component of this URI; returns **null** if **host** is not defined.|
| port​ | Obtains the port component of this URI; returns **-1** if **port** is not defined. The return value is a non-negative integer.|
| query​ | Obtains the query component of this URI; returns **null** if **query** is not defined.|
| fragment​ | Obtains the decoded fragment component of this URI; returns **null** if **fragment** is not defined.|
| path​ | Obtains the decoded path component of this URI; returns **null** if **path** is not defined.|
| equals(ob: Object) | Checks whether this URI is the same as another URI object. It immediately returns **false** if the given object is not a URI.|
| normalize​() | Normalizes the path of this URI. It constructs a new URI object if the path of the URI is not standard.|
| checkIsAbsolute​() | Checks whether this URI is an absolute URI (whether the scheme component is defined). It returns **true** if the URI is an absolute URI; otherwise, it returns **false**.|
| ConvertXml() | A no-argument constructor that creates a **ConvertXml** object.  |
| convert(xml: string, options: Object)  | Converts an XML text into a JavaScript object.|
| XmlSerializer(buffer: ArrayBuffer \| DataView, encoding?: string) | Creates and returns an **XmlSerializer** object. The **XmlSerializer** object passes two parameters. The first parameter is the memory of the **ArrayBuffer** or **DataView** type, and the second parameter is the file format (UTF-8 by default).|
| setAttributes(name: string, value: string): void | Sets attributes for the XML file.|
| addEmptyElement(name: string): void | Adds an empty element.|
| setDeclaration(): void | Sets a declaration for the XML file. Example: <? xml version="1.0"encoding="utf-8">|
| startElement(name: string): void | Writes the start tag based on the given element name.|
| endElement(): void | Writes the end tag of the element.|
| setNamespace(prefix: string, namespace: string): void | Sets the namespace for an element tag.|
| setComment(text: string): void | Sets the comment.|
| setCData(text: string): void | Sets the **CData** attribute.|
| setText(text: string): void | Sets the **Text** attribute.|
| setDocType(text: string): void | Sets the **DocType** attribute.|
| XmlPullParser(buffer: ArrayBuffer \| DataView, encoding?: string) | Creates and returns an **XmlPullParser** object. The **XmlPullParser** object passes two parameters. The first parameter is the memory of the **ArrayBuffer** or **DataView** type, and the second parameter is the file format (UTF-8 by default).|
| parse(option: ParseOptions): void | Parses XML information. **ParseOptions** contains five optional parameters: {supportDoctype?: boolean ignoreNameSpace?: boolean tagValueCallbackFunction?: (name: string, value: string) => boolean attributeValueCallbackFunction?: (name: string, value: string) => boolean) tokenValueCallbackFunction?: (eventType: EventType, value: ParseInfo) => boolean }. For **tokenValueCallbackFunction**, the first input parameter indicates the event type, and the second input parameter indicates the **info** interface that contains getters such as **getColumnNumber** and **getDepth**. You can use methods such as **info.getDepth()** to obtain information during the parsing.|
#### How to Use

Use the APIs as follows:


1. new URL(url: string,base?:string|URL)
```
let b = new URL('https://developer.mozilla.org'); // => 'https://developer.mozilla.org/'

let a = new URL( 'sca/./path/path/../scasa/text', 'http://www.example.com');
// => 'http://www.example.com/sca/path/scasa/text'
```
2. tostring():string
```
const url = new URL('http://10.0xFF.O400.235:8080/directory/file?query#fragment');
url.toString() // => 'http://10.0xff.o400.235:8080/directory/file?query#fragment'

const url = new URL("http://[FEDC:BA98:7654:3210:FEDC:BA98:7654:3210]:80/index.html");
url.toString() // => 'http://[fedc:ba98:7654:3210:fedc:ba98:7654:3210]/index.html'

const url = new URL("http://username:password@host:8080/directory/file?query#fragment");
url.toString() // => 'http://username:password@host:8080/directory/file?query#fragment'
```
3. toJSON():string
```
const url = new URL("https://developer.mozilla.org/en-US/docs/Web/API/URL/toString");
url.toJSON(); // =>  'https://developer.mozilla.org/en-US/docs/Web/API/URL/toString'
```
4. new URLSearchParams()
```
let params = new URLSearchParams('foo=1&bar=2');
```
5. new URLSearchParams(string)
```
params = new URLSearchParams('user=abc&query=xyz');
console.log(params.get('user'));
// Prints 'abc'
```
6. new URLSearchParams(obj)
```
const params = new URLSearchParams({
    user: 'abc',
    query: ['first', 'second']
});
console.log(params.getAll('query'));
// Prints [ 'first,second' ]
```
7. new URLSearchParams(iterable)
```
let params;

// Using an array
params = new URLSearchParams([
    ['user', 'abc'],
    ['query', 'first'],
    ['query', 'second'],
]);
console.log(params.toString());
// Prints 'user = abc & query = first&query = second'
```
8. has(name: string): boolean
```
console.log(params.has('bar')); // =>true
```
9. set(name: string, value string): void
```
params.set('baz', 3);
```
10. sort(): void
```
params .sort();
```
11. toString(): string
```
console.log(params .toString()); // =>bar=2&baz=3&foo=1'
```
12. keys(): iterableIterator\<string>
```
for(var key of params.keys()) {
  console.log(key);
} // =>bar  baz  foo
```
13. values(): iterableIterator\<string>
```
for(var value of params.values()) {
  console.log(value);
} // =>2  3  1
```
14. append(name: string, value: string): void
```
params.append('foo', 3); // =>bar=2&baz=3&foo=1&foo=3
```
15. delete(name: string): void
```
params.delete('baz'); // => bar=2&foo=1&foo=3
```
16. get(name: string): string
```
params.get('foo'); // => 1
```
17. getAll(name: string): string[]
```
params.getAll('foo'); // =>[ '1', '3' ]
```
18. entries(): iterableIterator<[string, string]>
```
for(var pair of searchParams.entries()) {
   console.log(pair[0]+ ', '+ pair[1]);
} // => bar, 2   foo, 1  foo, 3
```
19. forEach(): void
```
url.searchParams.forEach((value, name, searchParams) => {
  console.log(name, value, url.searchParams === searchParams);
});
// => foo 1 true
// => bar 2 true
```
20. urlSearchParams[Symbol.iterator]()
```
const params = new URLSearchParams('foo=bar&xyz=baz');
for (const [name, value] of params) {
    console.log(name, value);
}
// Prints:
// foo bar
// xyz bar
```


21. URI(str: string)
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
```
22. scheme
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.scheme        // => "http";
```
23. authority
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.authority     // => "gg:gaogao@www.baidu.com:99";
```
24. ssp
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.ssp "         // => gg:gaogao@www.baidu.com:99/path/path?query";
```
25. userinfo
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.userinfo      // => "gg:gaogao";
```
26. host
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.host          // => "www.baidu.com";
```
27. port
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.port          // => "99";
```
28. query
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.query         // => "query";
```
29. fragment
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.fragment      // => "fagment";
```
30. path
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.path          // => "/path/path";
```
31. equals(ob: Object)
```
let gaogao = new Uri.URI('http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/path1?query#fagment');
let gaogao1 = gaogao;
let res = gaogao.equals(gaogao1);
console.log(res);      // => true;
```
32. normalize()
```
let gaogao = new Uri.URI('http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/path/66./../././mm/.././path1?query#fagment');
let res = gaogao.normalize();
console.log(res.path);        // => "/path/path1"
console.log(res.toString());  // => "http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/path/path1?query#fagment"
```
33. checkIsAbsolute()
```
let gaogao = new Uri.URI('f/tp://username:password@www.baidu.com:88/path?query#fagment');
let res = gaogao.checkIsAbsolute();
console.log(res);              //=> false;
```
34. toString()
```
let gaogao = new Uri.URI('http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/../../path/.././../aa/bb/cc?query#fagment');
let res = gaogao.toString();
console.log(res.toString());     // => 'http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/../../path/.././../aa/bb/cc?query#fagment';
```


35. ConvertXml()
```
var convertml = new convertXml.ConvertXml();
```
36. convert(xml: string, options: Object)
```
var result = convertml.convert(xml, {compact: false, spaces: 4});
```
37. new XmlSerializer(buffer: ArrayBuffer | DataView, encoding?: string)
```

var arrayBuffer = new ArrayBuffer(1024);
var bufView = new DataView(arrayBuffer);
var thatSer = new xml.XmlSerializer(bufView);
```
38. setDeclaration(): void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setDeclaration() // => <?xml version="1.0" encoding="utf-8"?>;
```
39. setComment(text: string):void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setCommnet("Hello, World!"); // => <!--Hello, World!-->;
```
40. setCData(text: string) :void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setDocType('root SYSTEM "http://www.test.org/test.dtd"'); // => <![CDATA[root SYSTEM \"http://www.test.org/test.dtd\"]]>
```
41. setDocType(text: string):void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setDocType("foo"); // => <!DOCTYPE foo>
```
42. setNamespace(prefix: string, namespace: string): void
43. startElement(name: string): void
44. setAttributes(name: string, value: string): void
45. endElement(): void
46. setText(text: string): void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setNamespace("h", "http://www.w3.org/TR/html4/");
thatSer.startElement("table");
thatSer.setAttributes("importance", "high");
thatSer.setText("Happy");
endElement(); // => <h:table importance="high" xmlns:h="http://www.w3.org/TR/html4/">Happy</h:table>
```
47. addEmptyElement(name: string): void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.addEmptyElement("b"); // => <b/>
```
48. new (buffer: ArrayBuffer | DataView, encoding?: string)
```
var strXml =
            '<?xml version="1.0" encoding="utf-8"?>' +
            '<note importance="high" logged="true">' +
            '    <title>Happy</title>' +
            '</note>';
var arrayBuffer = new ArrayBuffer(strXml.length*2);
var bufView = new Uint8Array(arrayBuffer);
var strLen = strXml.length;
for (var i = 0; i < strLen; ++i) {
    bufView[i] = strXml.charCodeAt(i); // Set the ArrayBuffer mode.
}
var that = new xml.XmlPullParser(arrayBuffer);

```
49. parse(option: ParseOptions): void
```
var strXml =
            '<?xml version="1.0" encoding="utf-8"?>' +
            '<note importance="high" logged="true">' +
            '    <title>Happy</title>' +
            '</note>';
var arrayBuffer = new ArrayBuffer(strXml.length*2);
var bufView = new Uint8Array(arrayBuffer);
var strLen = strXml.length;
for (var i = 0; i < strLen; ++i) {
    bufView[i] = strXml.charCodeAt(i);
}
var that = new xml.XmlPullParser(arrayBuffer);
var arrTag = {};
arrTag[0] = '132';
var i = 1;
function func(key, value){
    arrTag[i] = 'key:'+key+' value:'+ value.getDepth();
    i++;
    return true;
}
var options = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func}
that.parse(options);
```

## js_util_module
### Introduction

The js_util_module provides the following classes:<br> **TextEncoder**: provides APIs to encode a string into a UTF-8 byte stream. **TextDecoder**: provides APIs to decode a byte stream into a string. **HelpFunction**: provides APIs to perform the callback and promise processing on functions, compile and output error codes, and format class strings. **encode**: provides APIs to use the Base64 encoding scheme to encode all bytes in a Unit8Array typed array into a new Unit8Array typed array or encode a byte array into a string. **decode**: provides APIs to use the Base64 encoding scheme to decode a Base64-encoded string or a Unit8Array typed array into a new Unit8Array typed array. **RationalNumber**: provides APIs to compare rational numbers and obtain numerators and denominators. **LruBuffer**: provides APIs to discard the least recently used data to make rooms for new elements when the buffer is full. The Least Recently Used (LRU) algorithm believes that the recently used data may be accessed again in the near future and the least accessed data is the least valuable data and should be removed from the buffer. **Scope**: provides APIs to define the valid range of a field. The constructor of this class creates comparable objects with lower and upper limits.
### Directory Structure

```
commonlibrary/ets_utils/js_util_module/
├── Class:TextEncoder                   # TextEncoder class
│   ├──  new TextEncoder()              # Used to create a TextEncoder object
│   ├──  encode()                       # encode method
│   ├──  encoding                       # encoding attribute
│   └──  encodeInto()                   # encodeInto method
├── Class:TextDecoder                   # TextDecoder class
│   ├──  new TextDecoder()              # Used to create a TextDecoder object
│   ├──  decode()                       # decode method
|   ├──  decodeWithStream()             # decodeWithStream method
│   ├──  encoding                       # encoding attribute
│   ├──  fatal                          # fatal attribute
│   └──  ignoreBOM                      # ignoreBOM attribute
├── printf()                            # printf method
├── getErrorString()                    # getErrorString method
├── callbackWrapper()                   # callbackWrapper method
├── promiseWrapper()                    # promiseWrapper method
├── Class:Base64                        # Base64 class
│   ├──  new Base64()                   # Used to create a Base64 object
│   ├──  encodeSync()                   # encodeSync method
│   ├──  encodeToStringSync()           # encodeToStringSync method
│   ├──  decodeSync()                   # decodeSync method
│   ├──  encode()                       # encode method
│   ├──  encodeToString()               # encodeToString method
│   └──  decode()                       # decode method
├── Class:RationalNumber                # RationalNumber class
│   ├──  new RationalNumber()           # Used to create a RationalNumber object
│   ├──  createRationalFromString()     # createRationalFromString method
│   ├──  compareTo()                    # compareTo method
│   ├──  equals()                       # equals method
│   ├──  valueOf()                      # valueOf method
│   ├──  getCommonDivisor()             # getCommonDivisor method
│   ├──  getDenominator()               # getDenominator method
│   ├──  getNumerator()                 # getNumerator method
│   ├──  isFinite()                     # isFinite method
│   ├──  isNaN()                        # isNaN method
│   ├──  isZero()                       # isZero method
│   └──  toString()                     # toString method
├── Class:LruBuffer                     # LruBuffer class
│   ├──  new LruBuffer()                # Used to create a LruBuffer object
│   ├──  updateCapacity()               # updateCapacity method
│   ├──  toString()                     # toString method
│   ├──  values()                       # values method
│   ├──  length                         # length attribute
│   ├──  getCapacity()                  # getCapacity method
│   ├──  clear()                        # clear method
│   ├──  getCreateCount()               # getCreateCount method
│   ├──  getMissCount()                 # getMissCount method
│   ├──  getRemovalCount()              # getRemovalCount method
│   ├──  getMatchCount()                # getMatchCount method
│   ├──  getPutCount()                  # getPutCount method
│   ├──  isEmpty()                      # isEmpty method
│   ├──  get()                          # get method
│   ├──  put()                          # put method
│   ├──  keys()                         # keys method
│   ├──  remove()                       # remove method
│   ├──  afterRemoval()                 # afterRemoval method
│   ├──  contains()                     # contains method
│   ├──  createDefault()                # createDefault method
│   ├──  entries()                      # entries method
│   └──  [Symbol.iterator]()            # Symboliterator method
|—— Class:Scope                         # Scope class
|   ├── constructor()                   # Used to create a Scope object
|   ├── toString()                      # toString method
|   ├── intersect()                     # intersect method
|   ├── intersect()                     # intersect method
|   ├── getUpper()                      # getUpper method
|   ├── getLower()                      # getLower method
|   ├── expand()                        # expand method
|   ├── expand()                        # expand method
|   ├── expand()                        # expand method
|   ├── contains()                      # contains method
|   ├── contains()                      # contains method
|   └── clamp()                         # clamp method
└── Class:Types                         # Types class
    ├── isAnyArrayBuffer()              # isAnyArrayBuffer method
    ├── isArrayBufferView()             # isArrayBufferView method
    ├── isArgumentsObject()             # isArgumentsObject method
    ├── isArrayBuffer()                 # isArrayBuffer method
    ├── isAsyncFunction()               # isAsyncFunction method
    ├── isBigInt64Array()               # isBigInt64Array method
    ├── isBigUint64Array()              # isBigUint64Array method
    ├── isBooleanObject()               # isBooleanObject method
    ├── isBoxedPrimitive()              # isBoxedPrimitive method
    ├── isDataView()                    # isDataView method
    ├── isDate()                        # isDate method
    ├── isExternal()                    # isExternal method
    ├── isFloat32Array()                # isFloat32Array method
    ├── isFloat64Array()                # isFloat64Array method
    ├── isGeneratorFunction()           # isGeneratorFunction method
    ├── isGeneratorObject()             # isGeneratorObject method
    ├── isInt8Array()                   # isInt8Array method
    ├── isInt16Array()                  # isInt16Array method
    ├── isInt32Array()                  # isInt32Array method
    ├── isMap()                         # isMap method
    ├── isMapIterator()                 # isMapIterator method
    ├── isModuleNamespaceObject()       # isModuleNamespaceObject method
    ├── isNativeError()                 # isNativeError method
    ├── isNumberObject()                # isNumberObject method
    ├── isPromise()                     # isPromise method
    ├── isProxy()                       # isProxy method
    ├── isRegExp()                      # isRegExp method
    ├── isSet()                         # isSet method
    ├── isSetIterator()                 # isSetIterator method
    ├── isSharedArrayBuffer()           # isSharedArrayBuffer method
    ├── isStringObject()                # isStringObject method
    ├── isSymbolObject()                # isSymbolObject method
    ├── isTypedArray()                  # isTypedArray method
    ├── isUint8Array()                  # isUint8Array method
    ├── isUint8ClampedArray()           # isUint8ClampedArray method
    ├── isUint16Array()                 # isUint16Array method
    ├── isUint32Array()                 # isUint32Array method
    ├── isWeakMap()                     # isWeakMap method
    └── isWeakSet()                     # isWeakSet method
```
### Usage

#### Available APIs


| API| Description|
| -------- | -------- |
| constructor(encoding? : string) | A constructor used to create a **TextDecoder** object. **encoding** indicates the encoding format. The default value is **UTF-8**, and the values **gb18030**, **gbk**, and **gb2312** are supported.|
| readonly encoding : string | Obtains the encoding format. Only **UTF-8** is supported.|
| encode(input : string) : Uint8Array | Encodes a string into a Uint8Array typed array.|
| encodeInto(input : string, dest : Uint8Array) : {read : number, written : number} | Encodes a string into a Unit8Array typed array, and stores the array. **dest** indicates the storage location, **read** indicates the number of encoded characters, and **written** indicates the number of bytes occupied by the encoded characters.|
| constructor(encoding? : string, options? : {fatal? : boolean, ignoreBOM? : boolean}) | A constructor used to create a **TextDecoder** object. **encoding** indicates the decoding format. **options** indicates certain attributes, where **fatal** specifies whether to throw an exception, and **ignoreBOM** specifies whether to ignore the BOM flag.|
| readonly encoding : string | Obtains the decoding format.|
| readonly fatal : boolean | Obtains the setting of whether to throw an exception.|
| readonly ignoreBOM : boolean | Obtains the setting of whether to ignore the BOM flag.|
| decode(input : Uint8Array, options?: { stream?: false }) : string | Decodes a Unit8Array typed array into a string. **input** indicates the data to decode, and **options** specifies whether additional data will be followed, with the default value **false**.|
| decodeWithStream(input : Uint8Array, options?: { stream?: false }) : string | Decodes a Unit8Array typed array into a string. **input** indicates the data to decode, and **options** specifies whether additional data will be followed, with the default value **false**.|
| encodeSync(src: Uint8Array): Uint8Array; | Uses the Base64 encoding scheme to synchronously encode all bytes in a Unit8Array typed array into a new Unit8Array typed array.|
| encodeToStringSync(src: Uint8Array): string; | Uses the Base64 encoding scheme to synchronously encode a Unit8Array typed array into a string.|
| decodeSync(src: Uint8Array \| string): Uint8Array; | Uses the Base64 encoding scheme to synchronously decode a Base64-encoded string or a Unit8Array typed array into a new Unit8Array typed array.|
| encode(src: Uint8Array): Promise\<Uint8Array\>; | Uses the Base64 encoding scheme to asynchronously encode all bytes in a Unit8Array typed array into a new Unit8Array typed array.|
| encodeToString(src: Uint8Array): Promise\<string\>; | Uses the Base64 encoding scheme to asynchronously encode a Unit8Array typed array into a string. It uses a promise to return the result.|
| decode(src: Uint8Array \| string): Promise\<Uint8Array\>; | Uses the Base64 encoding scheme to asynchronously decode a Base64-encoded string or a Unit8Array typed array into a new Unit8Array typed array.|
| static createRationalFromString(rationalString: string): RationalNumber | Creates a **RationalNumber** object based on the given string.|
| compareTo(another: RationalNumber): number | Compares this **RationalNumber** object with the given object.|
| equals(obj: object): number | Checks whether this **RationalNumber** object equals the given object.|
| valueOf(): number | Rounds the value of this **RationalNumber** object as an integer or a floating-point number.|
| static getCommonDivisor(number1: number, number2: number,): number | Obtains the greatest common divisor of two specified integers.|
| getDenominator(): number | Obtains the denominator of this **RationalNumber** object.|
| getNumerator(): number | Obtains the numerator of this **RationalNumber** object.|
| isFinite(): boolean | Checks whether this **RationalNumber** object represents a finite value.|
| isNaN(): boolean | Checks whether this **RationalNumber** object is a Not a Number (NaN).|
| isZero(): boolean | Checks whether this **RationalNumber** object is **0**.|
| toString(): string | Obtains the string representation of this **RationalNumber** object.|
| constructor(capacity?: number) | Default constructor used to create an **LruBuffer** instance. The default capacity of the buffer is 64.|
| updateCapacity(newCapacity: number): void | Changes the **LruBuffer** capacity. If the new capacity is less than or equal to **0**, an exception will be thrown.|
| toString(): string | Obtains the string representation of this **LruBuffer** object. |
| values(): V[] | Obtains all values in this buffer, listed from the most to the least recently used.|
| length: number | Obtains the total number of values in this buffer.|
| getCapacity(): number | Obtains the capacity of this buffer.|
| clear(): void | Clears key-value pairs from this buffer. **afterRemoval()** will be called to perform subsequent operations.|
| getCreateCount(): number | Obtains the number of return values for **createDefault()**.|
| getMissCount(): number | Obtains the number of times that the queried values are mismatched.|
| getRemovalCount(): number | Obtains the number of removals from this buffer.|
| getMatchCount​(): number | Obtains the number of times that the queried values are matched.|
| getPutCount(): number | Obtains the number of additions to this buffer.|
| isEmpty(): boolean | Checks whether this buffer is empty. This API returns **true** if the buffer does not contain any value.|
| get(key: K) : V \| undefined | Obtains the value of the specified key. This API returns the value of the key if a match is found in the buffer; otherwise, it returns **undefined**.|
| put(key: K , value: V): V | Adds a key-value pair to the buffer and outputs the value associated with the key. This API returns the existing value if the key already exists; otherwise, it returns the value added. If the key or value is null, an exception will be thrown.|
| keys(): K[ ] | Obtains all keys in this buffer, listed from the most to the least recently used.|
| remove​(key: K): V \| undefined |  Removes the specified key and its value from this buffer.|
| afterRemoval(isEvict: boolean, key: K, value : V, newValue : V):void | Performs subsequent operations after a value is removed.|
| contains(key: K): boolean | Checks whether this buffer contains the specified key. This API returns **true** if the buffer contains the specified key.|
| createDefault(key: K): V | Creates a value if the value of the specified key is not available.|
| entries(): [K,V] | Obtains a new iterator object that contains all key-value pairs in this buffer. The key and value of each pair are objects.|
| \[Symbol.iterator\](): [K,V] | Obtains a two-dimensional array in key-value pairs.|
| constructor(lowerObj: ScopeType, upperObj : ScopeType) | A constructor used to create a **Scope** object with the specified upper and lower limits.|
| toString(): string | Obtains a string representation that contains this **Scope**.|
| intersect(range: Scope): Scope | Obtains the intersection of this **Scope** and the given **Scope**.|
| intersect(lowerObj: ScopeType, upperObj: ScopeType): Scope | Obtains the intersection of this **Scope** and the given lower and upper limits.|
| getUpper(): ScopeType | Obtains the upper limit of this **Scope**.|
| getLower(): ScopeType | Obtains the lower limit of this **Scope**.|
| expand(lowerObj: ScopeType, upperObj:  ScopeType): Scope | Obtains the union set of this **Scope** and the given lower and upper limits.|
| expand(range: Scope): Scope | Obtains the union set of this **Scope** and the given **Scope**.|
| expand(value: ScopeType): Scope | Obtains the union set of this **Scope** and the given value.|
| contains(value: ScopeType): boolean | Checks whether a value is within this **Scope**.|
| contains(range: Scope): boolean | Checks whether a range is within this **Scope**.|
| clamp(value: ScopeType): ScopeType | Limits a value to this **Scope**.|
| function printf(format: string, ...args: Object[]): string | Prints the input content in a formatted string. **format** can contain zero or more format specifiers.|
| function getErrorString(errno: number): string | Obtains detailed information about a system error code.|
| function callbackWrapper(original: Function): (err: Object, value: Object) => void | Wraps an asynchronous function (or a function that returns a promise) into an error-first callback, which means that **(err, value) => ...** is used as the last parameter of the callback. In the callback, the first parameter indicates the cause of the rejection (the value is **null** if the promise has been resolved), and the second parameter indicates the resolved value.|
| function promiseWrapper(original: (err: Object, value: Object) => void): Object | Wraps a function that follows the error-first callback paradigm into a promise.|
| isAnyArrayBuffer(value: Object): boolean | Checks whether the input value is of the **ArrayBuffer** or **SharedArrayBuffer** type.|
| isArrayBufferView(value: Object): boolean | Checks whether the input value is of the **ArrayBufferView** type, which is a helper type representing any of the following: napi_int8_array, napi_uint8_array, napi_uint8_clamped_array, napi_int16_array, napi_uint16_array, napi_int32_array, napi_uint32_array, napi_float32_array, napi_float64_array, and DataView.|
| isArgumentsObject(value: Object): boolean | Checks whether the input value is of the **arguments** type.|
| isArrayBuffer(value: Object): boolean | Checks whether the input value is of the **ArrayBuffer** type.|
| isAsyncFunction(value: Object): boolean | Checks whether the input value is an asynchronous function.|
| isBigInt64Array(value: Object): boolean | Checks whether the input value is of the **BigInt64Array** type.|
| isBigUint64Array(value: Object): boolean | Checks whether the input value is of the **BigUint64Array** type.|
| isBooleanObject(value: Object): boolean | Checks whether the input value is of the **Boolean** type.|
| isBoxedPrimitive(value: Object): boolean | Checks whether the input value is of the **Boolean**, **Number**, **String**, or **Symbol** type.|
| isDataView(value: Object): boolean | Checks whether the input value is of the **DataView** type.|
| isDate(value: Object): boolean | Checks whether the input value is of the **Date** type.|
| isExternal(value: Object): boolean | Checks whether the input value is of the **native external** type.|
| isFloat32Array(value: Object): boolean | Checks whether the input value is of the **Float32Array** type.|
| isFloat64Array(value: Object): boolean | Checks whether the input value is of the **Float64Array** type.|
| isGeneratorFunction(value: Object): boolean | Checks whether the input value is a generator function.|
| isGeneratorObject(value: Object): boolean | Checks whether the input value is a generator object.|
| isInt8Array(value: Object): boolean | Checks whether the input value is of the **Int8Array** type.|
| isInt16Array(value: Object): boolean | Checks whether the input value is of the **Int16Array** type.|
| isInt32Array(value: Object): boolean | Checks whether the input value is of the **Int32Array** type.|
| isMap(value: Object): boolean | Checks whether the input value is of the **Map** type.|
| isMapIterator(value: Object): boolean | Checks whether the input value is of the **MapIterator** type.|
| isModuleNamespaceObject(value: Object): boolean | Checks whether the input value is a module namespace object.|
| isNativeError(value: Object): boolean | Checks whether the input value is of the **Error** type.|
| isNumberObject(value: Object): boolean | Checks whether the input value is a number object.|
| isPromise(value: Object): boolean | Checks whether the input value is a promise.|
| isProxy(value: Object): boolean | Checks whether the input value is a proxy.|
| isRegExp(value: Object): boolean | Checks whether the input value is a regular expression.|
| isSet(value: Object): boolean | Checks whether the input value is of the **Set** type.|
| isSetIterator(value: Object): boolean | Checks whether the input value is of the **SetIterator** type.|
| isSharedArrayBuffer(value: Object): boolean | Checks whether the input value is of the **SharedArrayBuffer** type.|
| isStringObject(value: Object): boolean | Checks whether the input value is a string object.|
| isSymbolObject(value: Object): boolean | Checks whether the input value is a symbol object.|
| isTypedArray(value: Object): boolean | Checks whether the input value is of the **TypedArray** type.|
| isUint8Array(value: Object): boolean | Checks whether the input value is of the **Uint8Array** type.|
| isUint8ClampedArray(value: Object): boolean | Checks whether the input value is of the **Uint8ClampedArray** type.|
| isUint16Array(value: Object): boolean | Checks whether the input value is of the **Uint16Array** type.|
| isUint32Array(value: Object): boolean | Checks whether the input value is of the **Uint32Array** type.|
| isWeakMap(value: Object): boolean | Checks whether the input value is of the **WeakMap** type.|
| isWeakSet(value: Object): boolean | Checks whether the input value is of the **WeakSet** type.|

Each format specifier in **printf()** is replaced with the converted value of the corresponding parameter. The following format specifiers are supported:
| Format Specifier| Description|
| -------- | -------- |
|    %s:  | String. It is used to convert all values except **BigInt**, **Object**, and **-0**.|
|    %d:  | Number. It is used to convert all values except **BigInt** and **Symbol**.|
|    %i:  | **parseInt(value, 10)**. It used to convert all values except **BigInt** and **Symbol**.|
|    %f:  | **parseFloat(value)**. It is used to convert all values except **Symbol**.|
|    %j:  | JSON. A circular reference in the parameter will be replaced with the string **'[Circular]'**.|
|    %o:  | A common JavaScript object represented in a string. It is similar to **util.inspect()** with the option **{ showHidden: true, showProxy: true }**. This will display a complete object, including innumerable properties and proxies.|
|    %O:  | Object. A string representation of an object with a common JavaScript object format. It is similar to **util.inspect()** without options. This will display a complete object, excluding innumerable properties and proxies.|
|    %c:  | This specifier is ignored and will jump any incoming CSS.|
|    %%:  | Single percent sign ('%'). This does not consume to-be-sampled parameters.|

#### How to Use
Use the APIs as follows:

1. readonly encoding()

```
import util from '@ohos.util'
var textEncoder = new util.TextEncoder();
var getEncoding = textEncoder.encoding();
```
2. encode()
```
import util from '@ohos.util'
var textEncoder = new util.TextEncoder();
var result = textEncoder.encode('abc');
```
3. encodeInto()
```
import util from '@ohos.util'
var textEncoder = new util.TextEncoder();
var obj = textEncoder.encodeInto('abc', dest);
```
4. textDecoder()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
```
5. readonly encoding()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var getEncoding = textDecoder.encoding();
```
6. readonly fatal()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var fatalStr = textDecoder.fatal();
```
7. readonly ignoreBOM()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var ignoreBom = textDecoder.ignoreBOM();
```
8. decode()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var result = textDecoder.decode(input, {stream : true});
```
9. decodeWithStream()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var result = textDecoder.decodeWithStream(input, {stream : true});
```
10. printf()
```
import util from '@ohos.util'
var format = "%%%o%%%i%s";
var value =  function aa(){};
var value1 = 1.5;
var value2 = "qwer";
var result = util.printf(format,value,value1,value2);
```
11. getErrorString()
```
import util from '@ohos.util'
var errnum = 13;
var result = util.getErrorString(errnum);
```
12. callbackWrapper()
```
import util from '@ohos.util'
async function promiseFn() {
    return Promise.resolve('value');
};
var cb = util.callbackWrapper(promiseFn);
cb((err, ret) => {
    expect(err).strictEqual(null);
    expect(ret).strictEqual('value');
})
```
13. promiseWrapper()
```
import util from '@ohos.util'
function aysnFun(str1, str2, callback) {
    if (typeof str1 === 'string' && typeof str1 === 'string') {
        callback(null, str1 + str2);
    } else {
        callback('type err');
    }
}
let newPromiseObj = util.promiseWrapper(aysnFun)("Hello", 'World');
newPromiseObj.then(res => {
    expect(res).strictEqual('HelloWorld');
})
```
14. encodeSync()
```
import util from '@ohos.util'
var that = new util.Base64();
var array = new Uint8Array([115,49,51]);
var result = that.encodeSync(array);
```
15. encodeToStringSync()
```
import util from '@ohos.util'
var that = new util.Base64();
var array = new Uint8Array([115,49,51]);
var result = that.encodeToStringSync(array);
```
16. decodeSync()
```
import util from '@ohos.util'
var that = new util.Base64()
var buff = 'czEz';
var result = that.decodeSync(buff);

```
17. encode()
```
import util from '@ohos.util'
var that = new util.Base64()
var array = new Uint8Array([115,49,51]);
await that.encode(array).then(val=>{
})
done()
```
18. encodeToString()
```
import util from '@ohos.util'
var that = new util.Base64()
var array = new Uint8Array([115,49,51]);
await that.encodeToString(array).then(val=>{
})
done()
```
19. decode()
```
import util from '@ohos.util'
var that = new util.Base64()
var buff = 'czEz';
await that.decode(buff).then(val=>{
})
done()
```
20. createRationalFromString()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(0, 0);
var res = pro.createRationalFromString("-1:2");
var result1 = res.valueOf();
```
21. compareTo()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var proc = new util.RationalNumber(3, 4);
var res = pro.compareTo(proc);
```
22. equals()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var proc = new util.RationalNumber(3, 4);
var res = pro.equals(proc);
```
23. valueOf()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var res = pro.valueOf();
```
24. getCommonDivisor()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(0, 0);
var res = pro.getCommonDivisor(4, 8);
```
25. getDenominator()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var res = pro.getDenominator();
```
26. getNumerator()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.getNumerator();
```
27. isFinite()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.isFinite();
```
28. isNaN()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.isNaN();
```
29. isZero()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.isZero();
```
30. toString()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.toString();
```
31. updateCapacity()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.updateCapacity(100);
```
32. toString()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.get(2);
pro.remove(20);
var result = pro.toString();
```
33. values()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.put(2,"anhu");
pro.put("afaf","grfb");
var result = pro.values();
```
34. length
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.put(1,8);
var result = pro.length;
```
35. getCapacity()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.getCapacity();
```
36. clear()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.clear();
```
37. getCreateCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(1,8);
var result = pro.getCreateCount();
```
38. getMissCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.get(2)
var result = pro.getMissCount();
```
39. getRemovalCount()
```

import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.updateCapacity(2);
pro.put(50,22);
var result = pro.getRemovalCount();

```
40. getMatchCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.get(2);
var result = pro.getMatchCount();
```
41. getPutCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.getPutCount();
```
42. isEmpty()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.isEmpty();
```
43. get()

```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.get(2);
```
44. put()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.put(2,10);
```
45. keys()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.keys();
```
46. remove()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.remove(20);
```
47. contains()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.contains(20);
```
48. createDefault()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.createDefault(50);
```
49. entries()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.entries();
```
50. \[Symbol.iterator\]()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro .put(2,10);
var result = pro[symbol.iterator]();
```
51. afterRemoval()
```
import util from '@ohos.util'
var arr = [ ];
class ChildLruBuffer extends util.LruBuffer
{
    constructor()
    {
        super();
    }
    static getInstance()
    {
        if(this.instance ==  null)
        {
            this.instance = new ChildLruBuffer();
        }
        return this.instance;
    }
    afterRemoval(isEvict, key, value, newValue)
    {
        if (isEvict === false)
        {
            arr = [key, value, newValue];
        }
    }
}
ChildLruBuffer.getInstance().afterRemoval(false,10,30,null)
```
A new constructor of **Scope** to implement the **compareTo** method.

```
class Temperature {
    constructor(value) {
        this._temp = value;
    }
    compareTo(value) {
        return this._temp >= value.getTemp();
    }
    getTemp() {
        return this._temp;
    }
    toString() {
        return this._temp.toString();
    }
}
```

52. constructor()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
```

53. toString()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var result = range.toString() // => [30,40]
```

54. intersect()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var rangeFir = new Scope(tempMiDF, tempMidS);
var result = range.intersect(rangeFir)  // => [35,39]
```

55. intersect()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var range = new Scope(tempLower, tempUpper);
var result = range.intersect(tempMiDF, tempMidS)  // => [35,39]
```

56. getUpper()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var result = range.getUpper() // => 40
```

57. getLower()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var result = range.getLower() // => 30
```

58. expand()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var range = new Scope(tempLower, tempUpper);
var result = range.expand(tempMiDF, tempMidS)  // => [30,40]
```

59. expand()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var range = new Scope(tempLower, tempUpper);
var rangeFir = new Scope(tempMiDF, tempMidS);
var result = range.expand(rangeFir) // => [30,40]
```

60. expand()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var range = new Scope(tempLower, tempUpper);
var result = range.expand(tempMiDF)  // => [30,40]
```

61. contains()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var range = new Scope(tempLower, tempUpper);
var result = range.contains(tempMiDF) // => true
```

62. contains()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var tempLess = new Temperature(20);
var tempMore = new Temperature(45);
var rangeSec = new Scope(tempLess, tempMore);
var result = range.contains(rangeSec) // => true
```

63. clamp()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var range = new Scope(tempLower, tempUpper);
var result = range.clamp(tempMiDF) // => 35
```
64. isAnyArrayBuffer()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isAnyArrayBuffer(new ArrayBuffer([]))
```
65. isArrayBufferView()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isArrayBufferView(new DataView(new ArrayBuffer(16)));
```
66. isArgumentsObject()
```
import util from '@ohos.util'
function foo() {
        var result = proc.isArgumentsObject(arguments);
    }
var f = foo();
```
67. isArrayBuffer()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isArrayBuffer(new ArrayBuffer([]));
```
68. isAsyncFunction()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isAsyncFunction(async function foo() {});
```
69. isBigInt64Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBigInt64Array(new Int16Array([]));
```
70. isBigUint64Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBigUint64Array(new Int16Array([]));
```
71. isBooleanObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBooleanObject(new Boolean(false));
```
72. isBoxedPrimitive()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBoxedPrimitive(new Boolean(false));
```
73. isDataView()
```
import util from '@ohos.util'
var proc = new util.Types();
const ab = new ArrayBuffer(20);
var result = proc.isDataView(new DataView(ab));
```
74. isDate()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isDate(new Date());
```
75. isExternal()
```
import util from '@ohos.util'
const data = util.createExternalType();
var reult13 = proc.isExternal(data);
```
76. isFloat32Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isFloat32Array(new Float32Array([]));
```
77. isFloat64Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isFloat64Array(new Float64Array([]));
```
78. isGeneratorFunction()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isGeneratorFunction(function* foo() {});
```
79. isGeneratorObject()
```
import util from '@ohos.util'
var proc = new util.Types();
function* foo() {}
const generator = foo();
var result = proc.isGeneratorObject(generator);
```
80. isInt8Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isInt8Array(new Int8Array([]));
```
81. isInt16Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isInt16Array(new Int16Array([]));
```
82. isInt32Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isInt32Array(new Int32Array([]));
```
83. isMap()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isMap(new Map());
```
84. isMapIterator()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isMapIterator(map.keys());
```
85. isModuleNamespaceObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isModuleNamespaceObject(util);
```
86. isNativeError()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isNativeError(new TypeError());
```
87. isNumberObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isNumberObject(new Number(0));
```
88. isPromise()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isPromise(Promise.resolve(42));
```
89. isProxy()
```
import util from '@ohos.util'
var proc = new util.Types();
const target = {};
const proxy = new Proxy(target, {});
var result = proc.isProxy(proxy);
```
90. isRegExp()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isRegExp(new RegExp('abc'));
```
91. isSet()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isSet(new Set());
```
92. isSetIterator()
```
import util from '@ohos.util'
var proc = new util.Types();
const set = new Set();
var result = proc.isSetIterator(set.keys());
```
93. isSharedArrayBuffer()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isSharedArrayBuffer(new ArrayBuffer([]));
```
94. isStringObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isStringObject(new String('foo'));
```
95. isSymbolObject()
```
import util from '@ohos.util'
var proc = new util.Types();
const symbols = Symbol('foo');
var result = proc.isSymbolObject(Object(symbols));
```
96. isTypedArray()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isTypedArray(new Float64Array([]));
```
97. isUint8Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint8Array(new Uint8Array([]));
```
98. isUint8ClampedArray()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint8ClampedArray(new Uint8ClampedArray([]));
```
99. isUint16Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint16Array(new Uint16Array([]));
```
100. isUint32Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint32Array(new Uint32Array([]));
```
101. isWeakMap()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isWeakMap(new WeakMap());
```
102. isWeakSet()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isWeakSet(new WeakSet());
```

## js_sys_module
###  Introduction
js_sys_module provides the following classes:<br>**Process**: provides APIs to obtain multiple IDs of a process, obtain and modify the working directory of a process, and exit and stop a process. **childprocess**:  provides APIs for a process to obtain the standard input and output of its child processes, send signals, and close its child processes.
### Directory Structure

```
commonlibrary/ets_utils/js_sys_module/
├── Class:PROCESS                   # Process class
├── Uid                             # UID attribute
├── Gid                             # GID attribute
├── EUid                            # EUID attribute
├── EGid                            # EGID attribute
├── Groups                          # Groups attribute
├── Pid                             # PID attribute
├── Ppid                            # PPID attribute
├── chdir()                         # chdir method
├── uptime()                        # uptime method
├── kill()                          # kill method
├── abort()                         # abort method
├── on()                            # on method
├── tid                             # tid method
├── getStartRealtime()              # getStartRealtime method
├── getAvailableCores()             # getAvailableCores method
├── getPastCputime()                # getPastCputime method
├── isIsolatedProcess()             # isIsolatedProcess method
├── is64Bit()                       # is64Bit method
├── isAppUid()                      # isAppUid method
├── getUidForName()                 # getUidForName method
├── getThreadPriority()             # getThreadPriority method
├── getSystemConfig()               # getSystemConfig method
├── getEnvironmentVar()             # getEnvironmentVar method
├── exit()                          # exit method
├── cwd()                           # cwd method
├── off()                           # off method
├── runCmd()                        # runCmd method
└─── Class:CHILDPROCESS             # ChildProcess class
    ├── close()                     # close method
    ├── kill()                      # kill method
    ├── getOutput()                 # getOutput method
    ├── getErrorOutput()            # getErrorOutput method
    ├── wait()                      # wait method
    ├── killed                      # killed attribute
    ├── pid                         # PID attribute
    ├── ppid                        # PPID attribute
    └── exitCode                    # exitCode attribute
|—— Class:CONSOLE
    ├── debug()                     # debug method
    ├── log()                       # log method
    ├── info()                      # info method
    ├── warn()                      # warn method
    ├── error()                     # error method
    ├── assert()                    # assert method
    ├── count()                     # count method
    ├── countReset()                # countReset method
    ├── dir()                       # dir method
    ├── dirxml()                    # dirxml method
    ├── group()                     # group method
    ├── groupCollapsed()            # groupCollapsed method
    ├── groupEnd()                  # groupEnd method
    ├── table()                     # table method
    ├── time()                      # time method
    ├── timeEnd()                   # timeEnd method
    ├── timeLog()                   # timeLog method
    ├── trace()                     # trace method
|—— Class:TIMER
    ├── setInterval()               # setInterval method
    ├── setTimeout()                # setTimeout method
    ├── clearInterval()             # clearInterval method
    ├── clearTimeout()              # clearTimeout method
```

### How to Use

#### Available APIs
| API| Description|
| -------- | -------- |
| const uid :number | Obtains the user identifier (UID) of this process.|
| const gid :number | Obtains the group identifier (GID) of this process.|
| const euid :number | Obtains the effective user identifier (EUID) of this process.|
| const egid :number | Obtains the effective group identifier (EGID) of this process.|
| const groups :number[] |  Obtains an array with supplementary group IDs.|
| const pid :number | Obtains the process ID (PID) of this process.|
| const ppid :number |  Obtains the parent process ID (PPID) of this process.|
| chdir(dir:string) :void | Changes the working directory of this process.|
| uptime() :number |  Obtains the running time of this process, in seconds.|
| Kill(pid:number, signal:number) :boolean | Sends a signal to the specified process to terminate it. The value **true** means that the signal is sent.|
| abort() :void | Aborts a process and generates a core file. It will cause the process to exit immediately.|
| on(type:string ,listener:EventListener) :void | Stores the events triggered by the user.|
| exit(code:number):void | Terminates this process.|
| cwd():string |  Obtains the working directory of this process.|
| off(type: string): boolean | Deletes the event stored by the user. The value **true** means that the event is deleted.|
| runCmd(command: string, options?: { timeout : number, killSignal : number \| string, maxBuffer : number }): ChildProcess |Forks a new process to run a shell command and returns the **ChildProcess** object. **command** indicates the shell command to run, and **options** indicates certain running parameters, such as **timeout**, **killsignal**, and **maxbuffer**, of the child process. If **timeout** is set, the child process sends the **kill** signal after the specified timeout reaches. **maxbuffer** is used to limit the maximum size of **stdout** and **stderr** that can be received.|
| wait(): Promise\<number>| Waits until the child process ends. It uses a promise to return the exit code of the child process.|
| getOutput(): Promise\<Uint8Array> |  Obtains the standard output of the child process.|
| getErrorOutput(): Promise\<Uint8Array> | Obtains the standard error output of the child process.|
| const tid:number | Obtains the TID of the process.|
| getStartRealtime() :number | Obtains the duration (in milliseconds) from the time the system starts to the time the process starts.|
| getAvailableCores() :number[] | Obtains the number of CPU cores available for the process on a multi-core device.|
| getPastCputime() :number | Obtains the CPU time (in milliseconds) from the time the process starts to the current time.|
| isIsolatedProcess(): boolean | Checks whether this process is isolated.|
| is64Bit(): boolean | Checks whether this process is running in a 64-bit environment.|
| isAppUid(v:number): boolean | Checks whether a UID belongs to the current app.|
| getUidForName(v:string): number | Obtains the process UID based on the process name.|
| getThreadPriority(v:number): number | Obtains the thread priority based on the TID.|
| getSystemConfig(name:number): number | Obtains the system configuration based on the configuration name.|
| getEnvironmentVar(name:string): string | Obtains the value of an environment variable.|
| close(): void | Closes the child process in running.|
| kill(signal: number \| string): void |  Sends a signal to the specified child process to terminate it.|
| readonly killed: boolean | Specifies whether the signal is sent. The value **true** means that the signal is sent.|
| readonly exitCode: number | Indicates the exit code of the child process.|
| readonly pid: number | Indicates the PID of the child process.|
| readonly ppid: number | Indicates the PPID of the process.|
| debug(message: string, ...arguments: any[]): void | print debug information. |
| log(message: string, ...arguments: any[]): void | print log information. |
| info(message: string, ...arguments: any[]): void | print info information. |
| warn(message: string, ...arguments: any[]): void | print warn information. |
| error(message: string, ...arguments: any[]): void | print error information. |
| assert(value?: Object, ...arguments: Object[]): void | if value is false，print arguments information. |
| count(label?: string): void | Counts the label name. |
| countReset(label?: string): void | Clear the count of label names. |
| dir(dir?: Object): void | Print the object content. |
| dirxml(...arguments: Object[]): void | print log information. |
| group(...arguments: Object[]): void | Indent one group |
| groupCollapsed(...arguments: Object[]): void | Indent one group |
| groupEnd(): void | Unindent one group. |
| table(tableData?: Object): void | Print data in tabular form. |
| time(label?: string): void | Start the clock. |
| timeEnd(label?: string): void | End the timer. |
| timeLog(label?: string, ...arguments: Object[]): void | Print current timing. |
| trace(...arguments: Object[]): void | Print current stack. |
|  setInterval(handler: Function \| string, delay: number, ...arguments: any[]): number | Timing to call callback function. |
|  setTimeout(handler: Function \| string, delay?: number, ...arguments: any[]): number | Call the callback function when the timing ends. |
|  clearInterval(intervalID?: number): void | Clear the timing callback. |
|  clearTimeout(timeoutID?: number): void |Clear the timing callback. |

#### How to Use

Use the APIs as follows:
1. uid()
```
uid(){
    var res =  Process.uid;
}
```
2. gid()
```
gid(){
    var result = Process.gid;
}
```
3. euid()
```
euid(){
    var and = Process.euid;
}
```
4. egid()
```
egid(){
    var resb = Process.egid;
}
```
5. groups()
```
groups(){
    var answer = Process.groups;
}
```
6. pid()
```
pid(){
    var result = Process.pid;
}
```
7. ppid()
```
ppid(){
    var result = Process.ppid;
}
```
8. chdir()
```
chdir(){
    Process.chdir("123456");
}
```
9. uptime()
```
uptime(){
    var num = Process.uptime();
}
```
10. kill()
```
kill(){
    var ansu = Process.kill(5,23);
}
```
11. abort()
```
abort(){
    Process.abort();
}
```
12. on()
```
on(){
    function add(num){
        var value = num + 5;
        return value;
    }
    Process.on("add",add);
}
```
13. exit()
```
exit(){
    Process.exit(15);
}
```
14. Cwd()
```
Cwd(){
    var result = Process.cwd();
}
```
15. off()

```
off(){
    var result =  Process.off("add");
}
```
16. runCmd()
```
runCmd(){
    var child = process.runCmd('echo abc')
    // killSignal can be a number or string.
    var child = process.runCmd('echo abc;', {killSignal : 'SIGKILL'});
    var child = process.runCmd('sleep 5; echo abc;', {timeout : 1, killSignal : 9, maxBuffer : 2})
}
```
17. wait()
```
wait()
{
    var child = process.runCmd('ls')
    var status = child.wait();
    status.then(val => {
        console.log(val);
    })
}
```
18. getOutput()
```
getOutput(){
    var child = process.runCmd('echo bcd;');
    var res = child.getOutput();
    child.wait();
    res.then(val => {
        console.log(val);
    })
}
```
19. getErrorOutput()
```
getErrorOutput(){
    var child = process.runCmd('makdir 1.txt'); // execute an error command
    var res = child.getErrorOutput();
    child.wait();
    res.then(val => {
        console.log(val);
    })
}
```
20. close()
```
close(){
    var child =  process.runCmd('ls; sleep 5s;')
    var result = child.close()
}
```
21. kill()
```
kill(){
    var child =  process.runCmd('ls; sleep 5s;')
    var result = child.kill('SIGHUP');
    child.wait();
    var temp = child.killed;
}
```
22. killed
```
{
    var child = process.runCmd('ls; sleep 5;')
    child.kill(3);
    var killed_ = child.killed;
    child.wait();
}
```
23. exitCode
```
{
    var child = process.runCmd('ls; sleep 5;')
    child.kill(9);
    child.wait();
    var exitCode_ = child.exitCode;
}
```
24. pid
```
pid
{
    var child = process.runCmd('ls; sleep 5;')
    var pid_ = child.pid;
    child.wait();
}
```
25. ppid
```
ppid
{
    var child = process.runCmd('ls; sleep 5;')
    var ppid_ = child.ppid;
    child.wait();
}
```
26. tid
```
tid(){
    var ansu = Process.tid;
}
```
27. isIsolatedProcess()
```
isIsolatedProcess(){
    var ansu = Process.isIsolatedProcess()();
}
```
28. isAppUid()
```
isAppUid(){
    var ansu = Process.isAppUid(10000);
}
```
29. is64Bit()
```
is64Bit(){
    var ansu = Process.is64Bit();
}
```
30. getUidForName()
```
getUidForName(){
    var buf = "root";
    var ansu = Process.getUidForName(buf);
}
```
31. getEnvironmentVar()
```
getEnvironmentVar(){
    var ansu = Process.getEnvironmentVar('USER');
}
```
32. getAvailableCores()
```
getAvailableCores(){
    var ansu = Process.getAvailableCores();
}
```
33. getThreadPriority()
```
getThreadPriority(){
    var result = Process.getTid();
    var ansu = getThreadPriority(result);
}
```
34. getStartRealtime()
```
getStartRealtime(){
    var ansu = Process.getStartRealtime();
}
```
35. getPastCputime()
```
getPastCputime(){
    var ansu = Process.getPastCputime();
}
```
36. getSystemConfig()
```
getSystemConfig(){
    var _SC_ARG_MAX = 0;
    var ansu = Process.getSystemConfig(_SC_ARG_MAX)
}
```
37.console.debug()
```
console.debug("print debug log");
}
```
38.console.log()
```
console.debug("print log");
}
```
39.console.info()
```
console.debug("print info log");
}
```
40.console.warn()
```
console.debug("print warn log");
}
```
41.console.error()
```
console.debug("print error log");
}
```
42.console.assert()
```
for (let number = 2; number <= 5; number++) {
    console.assert(number % 2 === 0, "error");
}
```
43.console.count()
```
console.count("myObj");
```
44.console.countReset()
```
console.count("myObj");
console.countReset("myObj");
```
45.console.dir()
```
function cat(name, age, score){
  this.name = name;
  this.age = age;
  this.score = score;
}
var c = new cat("ohos", 2, [6,8,7]);
console.dir(c);
```
46.console.dirxml()
```
console.xml("print log");
```
47.console.group()
```
console.group();
```
48.console.groupCollapsed()
```
console.groupCollapsed();
```
49.console.groupEnd()
```
console.groupEnd();
```
50.console.table()
```
var languages = {
  csharp: { name: "C#", paradigm: "undefined" },
  fsharp: { name: "F#", paradigm: "functional" }
};
console.table(languages);
```
51.console.time()
```
console.time("timer1");
```
52.console.timeEnd()
```
console.time("timer1");
console.timeEnd("timer1");
```
53.console.timeLog()
```
console.time("timer1");
console.timeLog("timer1");
```
54.console.trace()
```
console.trace();
```
55.setInterval()
```
function callback() {
  console.log("setInterval");
};
setInterval(callback, 100);
```
55.setTimeout()
```
function callback() {
  console.log("setTimeout");
};
setTimeout(callback, 100);
```
55.clearInterval()
```
function callback() {
  console.log("clearInterval");
};
var myVar = setInterval(callback, 1000);
clearInterval(myVar);
```
56.clearTimeout()
```
function callback() {
  console.log("clearTimeout");
};
var myVar = setTimeout(callback, 1000);
clearTimeout(myVar);
```

## js_concurrent_module

### Introduction

The js_concurrent_module provides the worker thread, which communicates with the host thread through **postMessage**.

### Available APIs
For details about the API implementation, see js_worker_module/worker.

#### Worker Object

Object used by the host thread to communicate with the worker thread.

##### APIs

1.

- API

|constructor(scriptURL:string, options?:WorkerOptions) | Constructor used to create a worker object.|
|---|---|

- Example

You can use any of the following methods to create a worker thread, depending on whether the **workers** directory that stores the **worker.ts** file is at the same level as the **pages** directory and whether the FA or stage model is in use:

(1) In the FA model, the **workers** and **pages** directories are at the same level.
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker("workers/worker.js", {name:"first worker"});
```
(2) In the FA model, the **workers** and **pages** directories are at different levels.
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker("../workers/worker.js", {name:"first worker"});
```
(3) In the stage model, the **workers** and **pages** directories are at the same level.
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker('entry/ets/workers/worker.ts');
```
(4) In the stage model, the **workers** and **pages** directories are at different levels.
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker('entry/ets/pages/workers/worker.ts');
```
scriptURL in the stage model — Description of "entry/ets/workers/worker.ts".
- **entry**: value of the **name** attribute under **module** in the **module.json5** file.
- **ets**: programming language in use.
- **worker.ts**: file for the module. You can also use a **worker.js** file.

Depending on whether the **workers** and **pages** directories are at the same level, you may need to configure the **buildOption** attribute in the **build-profile.json5** file.

(1) If the **workers** and **pages** directories are at the same level, the configuration is optional.

In the FA model:
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/MainAbility/workers/worker.js"
      ]
    }
  }
```
In the stage model:
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/workers/worker.ts"
      ]
    }
  }
```
(2) If the **workers** and **pages** directories are at different levels, the configuration is mandatory.

In the FA model:
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/workers/worker.js"
      ]
    }
  }
```
In the stage model (the following assumes that the **workers** directory is under the **pages** directory):
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/pages/workers/worker.ts"
      ]
    }
  }
```
2.

- API

| postMessage(message:Object, options?:PostMessageOptions)  | Sends a message to the worker thread. |
|---|---|
| postMessage(message:Object, transfer:ArrayBuffer[])  | Sends a message to the worker thread. |

- Examples

```
// Example 1
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// Example 2
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
var buffer = new ArrayBuffer(8);
worker.postMessage(buffer, [buffer]);
```

3.

- API

| on(type:string, listener:EventListener)  | Adds an event listener to the worker. |
|---|---|

- Examples

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.on("alert", (e)=>{
     console.log("worker on...");
});
```

4.

- API

| once(type:string, listener:EventListener)  | Adds an event listener to the worker and removes the event listener automatically after it is invoked once. |
|---|---|

- Examples

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.once("alert", (e)=>{
    console.log("worker once...");
});
```

5.

- API

| off(type:string, listener?:EventListener)  | Removes an event listener for the worker. |
|---|---|

- Examples

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.off("alert");
```

6.

- API

| terminate()  | Terminates the worker thread to stop the worker from receiving messages. |
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.terminate();
```

7.

- API

| removeEventListener(type:string, listener?:EventListener)  | Removes an event listener for the worker. |
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.removeEventListener("alert", (e)=>{
    console.log("worker removeEventListener...");
});
```

8.

- API

| dispatchEvent(event: Event)  | Dispatches the event defined for the worker. |
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.dispatchEvent({type:"alert"});
```

9.

- API

| removeAllListener()  | Removes all event listeners for the worker. |
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.removeAllListener();
```

##### Attributes

1.

- Attribute

| onexit?:(code:number)=>void  | Event handler to be called when the worker thread exits. The handler is executed in the host thread. |
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onexit = function(e) {
    console.log("onexit...");
}
```

2.

- Attribute

| onerror?:(ev:ErrorEvent)=>void  | Event handler to be called when an exception occurs during worker execution. The event handler is executed in the host thread. |
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onerror = function(e) {
    console.log("onerror...");
}
```

3.

- Attribute

| onmessage?:(ev:MessageEvent)=>void  | Event handler to be called when the host thread receives a message sent by the worker thread through **parentPort.postMessage**. The event handler is executed in the host thread.|
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onmessage = function(e) {
    console.log("onmessage...");
}
```

4.

- Attribute

| onmessageerror?:(event:MessageEvent)=>void  | Event handler to be called when the worker thread receives a message that cannot be serialized. The event handler is executed in the host thread.|
|---|---|

- Example

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onmessageerror = function(e) {
    console.log("onmessageerror...");
}
```

#### parentPort Object

Object of the worker thread used to communicate with the host thread.

##### APIs

1.

- API

| postMessage(message:Object, options?:PostMessageOptions)  | Sends a message to the host thread from the worker thread.|
|---|---|
| postMessage(message:Object, transfer:ArrayBuffer[])  | Sends a message to the host thread from the worker thread. |

- Example

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessage = function(e) {
    parentPort.postMessage("hello world from worker.js");
}
```

2.

- API

| close()  | Terminates the worker thread to stop the worker from receiving messages. |
|---|---|

- Example

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessage = function(e) {
    parentPort.close();
}
```

##### Attributes

1.

- Attribute

| onmessage?:(event:MessageEvent)=>void  | Event handler to be called when the host thread receives a message sent by the worker thread through **parentPort.postMessage**. The event handler is executed in the worker thread. |
|---|---|

- Example

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessage = function(e) {
    console.log("receive main.js message");
}
```

2.

- Attribute

| onerror?:(ev: ErrorEvent)=>void  | Event handler to be called when an exception occurs during worker execution. The event handler is executed in the worker thread. |
|---|---|

- Example

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onerror = function(e) {
    console.log("onerror...");
}

```

3.

- Attribute

| onmessageerror?:(event: MessageEvent)=>void  | Event handler to be called when the worker thread receives a message that cannot be deserialized. The event handler is executed in the worker thread. |
|---|---|

- Example

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessageerror = function(e) {
    console.log("onmessageerror...");
}
```


# Repositories Involved

[arkcompiler_ets_runtime](https://gitee.com/openharmony/arkcompiler_ets_runtime/blob/master/README_zh.md)
[arkui_ace_engine](https://gitee.com/openharmony/arkui_ace_engine/blob/master/README_zh.md)
[arkui_napi](https://gitee.com/openharmony/arkui_napi/blob/master/README_zh.md)

# ets_utils组件
ets_utils组件共提供四个子模块，分别是：js_api_module、js_util_module、js_sys_module和js_concurrent_module，以下内容将详细介绍各个子模块的简介、目录、说明和涉及仓等相关内容。

# 子模块
## 1. js_api_module子模块
### 1.1. 简介

URL接口用于解析，构造，规范化和编码 URLs。 URL的构造函数创建新的URL对象。 以便对URL的已解析组成部分或对URL进行更改。URLSearchParams 接口定义了一些实用的方法来处理 URL 的查询字符串。

URI表示统一资源标识符引用。

xml表示指可扩展标记语言。

XmlSerializer接口用于生成一个xml文件。 XmlSerializer的构造函数创建新的XmlSerializer对象，调用XmlSerializer对象的方法生成一个xml文件。XmlPullParser 接口用于解析已有的xml文件，XmlPullParser的构造函数创建新的XmlPullParser对象，调用XmlPullParser对象的方法解析xml。

### 1.2. 目录

```
commonlibrary/ets_utils/js_api_module/
├── Class:URL                                                                     # URL类
│   ├── new URL(input[, base])                                                    # 创建URL对象
│   ├── hash                                                                      # hash属性
│   ├── host                                                                      # host属性
│   ├── hostname                                                                  # hostname属性
│   ├── href                                                                      # href属性
│   ├── origin                                                                    # origin属性
│   ├── password                                                                  # password属性
│   ├── pathname                                                                  # pathname属性
│   ├── port                                                                      # port属性
│   ├── protocol                                                                  # protocol属性
│   ├── search                                                                    # search属性
│   ├── searchParams                                                              # searchParams属性
│   ├── username                                                                  # username属性
│   ├── toString()                                                                # toString方法
│   └── toJSON()                                                                  # toJSON方法
├── Class: URLSearchParams                                                        # URLSearchParams类
│   ├── new URLSearchParams()                                                     # 创建URLSearchParams对象
│   ├── new URLSearchParams(string)                                               # 创建URLSearchParams对象
│   ├── new URLSearchParams(obj)                                                  # 创建URLSearchParams对象
│   ├── new URLSearchParams(iterable)                                             # 创建URLSearchParams对象
│   ├── append(name, value)                                                       # append方法
│   ├── delete(name)                                                              # delete方法
│   ├── entries()                                                                 # entries方法
│   ├── forEach(fn[, thisArg])                                                    # forEach方法
│   ├── get(name)                                                                 # get方法
│   ├── getAll(name)                                                              # getAll方法
│   ├── has(name)                                                                 # has方法
│   ├── keys()                                                                    # keys方法
│   ├── set(name, value)                                                          # set方法
│   ├── sort()                                                                    # sort方法
│   ├── toString()                                                                # toString方法
│   ├── values()                                                                  # values方法
│   └── urlSearchParams[Symbol.iterator]()                                        # 创建URLSearchParams对象
├── Class:URI                                                                     # URI类
│   ├── URI(str: string)                                                          # 创建URI对象
│   ├── scheme                                                                    # scheme属性
│   ├── authority                                                                 # authority属性
│   ├── ssp                                                                       # ssp属性
│   ├── userinfo                                                                  # userinfo属性
│   ├── host                                                                      # host属性
│   ├── port                                                                      # port属性
│   ├── query                                                                     # query属性
│   ├── fragment                                                                  # fragment属性
│   ├── path                                                                      # path属性
│   ├── equals(ob: Object)                                                        # equals方法
│   ├── normalize()                                                               # normalize方法
│   ├── checkIsAbsolute()                                                         # checkIsAbsolute方法
│   ├── normalize()                                                               # normalize方法
│   └── toString()                                                                # toString方法
├── Class:ConvertXml                                                              # ConvertXml类
│   ├── ConvertXml()                                                              # 创建ConvertXml类对象
│   └── convert(xml: string, options: Object)                                     # convert方法
├── Class:XmlSerializer                                                           # XmlSerializer类
│   ├── new XmlSerializer(buffer: ArrayBuffer | DataView, encoding?: string)      # 创建XmlSerializer类对象
│   ├── setAttributes(name: string, value: string)                                # 设置Attributes方法
│   ├── addEmptyElement(name: string)                                             # 添加一个空元素方法
│   ├── setDeclaration()                                                          # 设置Declaration方法
│   ├── startElement(name: string)                                                # 设置开始元素方法
│   ├── endElement()                                                              # 设置结束元素方法
│   ├── setNamespace(prefix: string, namespace: string)                           # 设置命名空间方法
│   ├── setCommnet(text: string)                                                  # 设置Commnet方法
│   ├── setCData(text: string)                                                    # 设置CData方法
│   ├── setText(text: string)                                                     # 设置Text方法
│   └── setDocType(text: string)                                                  # 设置DocType方法
├── Class: XmlPullParser                                                          # XmlPullParser类
│   ├── new (buffer: ArrayBuffer | DataView, encoding?: string)                   # 创建XmlPullParser对象
│   └── parse(option: ParseOptions)                                               # parse方法
├── alloc()                                                                       # 创建Buffer实例并初始化
├── allocUninitializedFromPool()                                                  # 在池中创建Buffer实例
├── allocUninitialized()                                                          # 创建Buffer实例
├── byteLength()                                                                  # 按编码返回字节数
├── compare()                                                                     # Buffer数据比较
├── concat()                                                                      # 粘接Buffer数组
├── from()                                                                        # 创建Buffer实例
├── isBuffer()                                                                    # 判断是否为Buffer
├── isEncoding()                                                                  # 创建Buffer实例
├── transcode()                                                                   # 转码
├── Class: Buffer                                                                 # Buffer类
│   ├── length                                                                    # length属性
│   ├── buffer                                                                    # buffer属性
│   ├── byteOffset                                                                # byteOffset属性
│   ├── fill()                                                                    # 填充数据
│   ├── compare()                                                                 # Buffer数据比较
│   ├── copy()                                                                    # 复制数据
│   ├── equals()                                                                  # 比较实例是否相等
│   ├── includes()                                                                # 检查对象是否包含值
│   ├── indexOf()                                                                 # 查找索引
│   ├── keys()                                                                    # 返回包含key值的迭代器
│   ├── values()                                                                  # 返回包含value值的迭代器
│   ├── entries()                                                                 # 返回包含key和value的迭代器
│   ├── lastIndexOf()                                                             # 反向查找索引
│   ├── readBigInt64BE()                                                          # 读取有符号的大端序64位整数
│   ├── readBigInt64LE()                                                          # 读取有符号的小端序64位整数
│   ├── readBigUInt64BE()                                                         # 读取无符号的大端序64位整数
│   ├── readBigUInt64LE()                                                         # 读取无符号的小端序64位整数
│   ├── readDoubleBE()                                                            # 读取64位大端序双精度值
│   ├── readDoubleLE()                                                            # 读取64位小端序双精度值
│   ├── readFloatBE()                                                             # 读取32位大端序浮点数
│   ├── readFloatLE()                                                             # 读取32位小端序浮点数
│   ├── readInt8()                                                                # 读取有符号的8位整数
│   ├── readInt16BE()                                                             # 读取有符号的大端序16位整数
│   ├── readInt16LE()                                                             # 读取有符号的小端序16位整数
│   ├── readInt32BE()                                                             # 读取有符号的大端序32位整数
│   ├── readInt32LE()                                                             # 读取有符号的小端序32位整数
│   ├── readIntBE()                                                               # 读取有符号的大端序整数
│   ├── readIntLE()                                                               # 读取有符号的小端序整数
│   ├── readUInt8()                                                               # 读取8位无符号整数
│   ├── readUInt16BE()                                                            # 读取无符号的大端序16位整数
│   ├── readUInt16LE()                                                            # 读取无符号的小端序16位整数
│   ├── readUInt32BE()                                                            # 读取无符号的大端序32位整数
│   ├── readUInt32LE()                                                            # 读取无符号的小端序32位整数
│   ├── readUIntBE()                                                              # 读取无符号的大端序整数
│   ├── readUIntLE()                                                              # 读取无符号的小端序整数
│   ├── subarray()                                                                # 子Buffer
│   ├── swap16()                                                                  # 以16位为基础交换字节顺序
│   ├── swap32()                                                                  # 以32位为基础交换字节顺序
│   ├── swap64()                                                                  # 以64位为基础交换字节顺序
│   ├── toJSON()                                                                  # 转为JSON格式对象
│   ├── toString()                                                                # 转成字符串
│   ├── write()                                                                   # 写入字符串
│   ├── writeBigInt64BE()                                                         # 写入有符号的大端序64位整数
│   ├── writeBigInt64LE()                                                         # 写入有符号的小端序64位整数
│   ├── writeBigUInt64BE()                                                        # 写入无符号的大端序64位整数
│   ├── writeBigUInt64LE()                                                        # 写入无符号的小端序64位整数
│   ├── writeDoubleBE()                                                           # 写入64位大端序双浮点型数据
│   ├── writeDoubleLE()                                                           # 写入64位小端序双浮点型数据
│   ├── writeFloatBE()                                                            # 写入32位大端序浮点型数据
│   ├── writeFloatLE()                                                            # 写入32位小端序浮点型数据
│   ├── writeInt8()                                                               # 写入8位有符号整数
│   ├── writeInt16BE()                                                            # 写入有符号的大端序16位整数
│   ├── writeInt16LE()                                                            # 写入有符号的小端序16位整数
│   ├── writeInt32BE()                                                            # 写入有符号的大端序32位整数
│   ├── writeInt32LE()                                                            # 写入有符号的大端序16位整数
│   ├── writeIntBE()                                                              # 写入有符号的大端序整数
│   ├── writeIntLE()                                                              # 写入有符号的小端序整数
│   ├── writeUInt8()                                                              # 写入8位无符号整数
│   ├── writeUInt16BE()                                                           # 写入无符号的大端序16位整数
│   ├── writeUInt16LE()                                                           # 写入无符号的小端序16位整数
│   ├── writeUInt32BE()                                                           # 写入无符号的大端序32位整数
│   ├── writeUInt32LE()                                                           # 写入无符号的小端序32位整数
│   ├── writeUIntBE()                                                             # 写入无符号的大端序整数
│   └── writeUIntLE()                                                             # 写入无符号的小端序整数
└── Class: Blob                                                                   # Blob类
    ├── constructor()                                                             # 构造函数
    ├── size                                                                      # size属性
    ├── type                                                                      # type属性
    ├── arrayBuffer()                                                             # 获取ArrayBuffer对象
    ├── slice()                                                                   # 返回切割后的对象
    └── text()                                                                    # 返回文本
```

### 1.3. 说明

#### 1.3.1. 接口说明


| 接口名 | 说明 |
| -------- | -------- |
| URL(url: string,base?:string \| URL) | 创建并返回一个URL对象，该URL对象引用使用绝对URL字符串，相对URL字符串和基本URL字符串指定的URL。 |
| tostring():string | 该字符串化方法返回一个包含完整 URL 的 USVString。它的作用等同于只读的 URL.href。 |
| toJSON():string | 该方法返回一个USVString，其中包含一个序列化的URL版本。 |
| new URLSearchParams() | URLSearchParams() 构造器无入参，该方法创建并返回一个新的URLSearchParams 对象。 开头的'?' 字符会被忽略。 |
| new URLSearchParams(string) | URLSearchParams(string) 构造器的入参为string数据类型，该方法创建并返回一个新的URLSearchParams 对象。 开头的'?' 字符会被忽略。 |
| new URLSearchParams(obj) | URLSearchParams(obj) 构造器的入参为obj数据类型，该方法创建并返回一个新的URLSearchParams 对象。 开头的'?' 字符会被忽略。 |
| new URLSearchParams(iterable) | URLSearchParams(iterable) 构造器的入参为iterable数据类型，该方法创建并返回一个新的URLSearchParams 对象。 开头的'?' 字符会被忽略。 |
| has(name: string): boolean | 检索searchParams对象中是否含有name。有则返回true，否则返回false。 |
| set(name: string, value string): void |  检索searchParams对象中是否含有key为name的键值对。没有的话则添加该键值对，有的话则修改对象中第一个key所对应的value，并删除键为name的其余键值对。 |
| sort(): void | 根据键的Unicode代码点，对包含在此对象中的所有键/值对进行排序，并返回undefined。 |
| toString(): string | 根据searchParams对象,返回适用在URL中的查询字符串。 |
| keys(): iterableIterator\<string> | 返回一个iterator，遍历器允许遍历对象中包含的所有key值。 |
| values(): iterableIterator\<string> | 返回一个iterator，遍历器允许遍历对象中包含的所有value值。 |
| append(name: string, value: string): void | 在searchParams对象中插入name, value键值对。 |
| delete(name: string): void | 遍历searchParams对象，查找所有的name,删除对应的键值对。 |
| get(name: string): string | 检索searchParams对象中第一个name,返回name键对应的值。 |
| getAll(name: string): string[] | 检索searchParams对象中所有name,返回name键对应的所有值。 |
| entries(): iterableIterator<[string, string]> | 返回一个iterator，允许遍历searchParams对象中包含的所有键/值对。 |
| forEach(): void | 通过回调函数来遍历URLSearchParams实例对象上的键值对。 |
| urlSearchParams\[Symbol.iterator]() | 返回查询字符串中每个名称-值对的ES6迭代器。迭代器的每个项都是一个JavaScript数组。 |
| URI​(str: string) | 通过解析给定入参（String str）来构造URI。此构造函数严格按照RFC 2396附录A中的语法规定解析给定字符串。 |
| scheme​ | 返回此 URI 的scheme部分，如果scheme未定义，则返回 null |
| authority​ | 返回此 URI 的解码authority部分，如果authority未定义，则返回 null。 |
| ssp​ |  返回此 URI 的解码scheme-specific部分。 |
| userinfo​ | 返回此 URI 的解码userinfo部分。包含passworld和username。 |
| host​ | 返回此 URI 的host部分，如果host未定义，则返回 null。 |
| port​ | 返回此 URI 的port部分，如果port未定义，则返回 -1。URI 的port组件（如果已定义）是一个非负整数。 |
| query​ | 返回此 URI 的query部分，如果query未定义，则返回 null。 |
| fragment​ | 返回此 URI 的解码fragment组件，如果fragment未定义，则返回 null。|
| path​ | 返回此 URI 的解码path组件，如果path未定义，则返回 null。 |
| equals(ob: Object) | 测试此 URI 是否与另一个对象相等。如果给定的对象不是 URI，则此方法立即返回 false。 |
| normalize​() | 规范化这个 URI 的路径。如果这个 URI 的path不规范，将规范后构造一个新 URI对象返回。 |
| checkIsAbsolute​() | 判断这个 URI 是否是绝对的。当且仅当它具有scheme部分时，URI 是绝对的，返回值为true，否则返回值为false。 |
| ConvertXml() | 用于构造ConvertXml类对象的构造函数。此构造函数无需传入参数。 |
| convert(xml: string, options: Object)  | 返回按选项要求转化xml字符串的JavaScrip对象。 |
| XmlSerializer(buffer: ArrayBuffer \| DataView, encoding?: string) | 创建并返回一个XmlSerializer对象，该XmlSerializer对象传参两个第一参数是ArrayBuffer或DataView一段内存，第二个参数为文件格式（默认为UTF-8）。 |
| setAttributes(name: string, value: string): void | 给xml文件中写入属性Attributes属性。 |
| addEmptyElement(name: string): void | 写入一个空元素。 |
| setDeclaration(): void | 设置Declaration使用编码写入xml声明。例如：<？xml version=“1.0”encoding=“utf-8”> |
| startElement(name: string): void | 写入具有给定名称的elemnet开始标记。|
| endElement(): void | 写入元素的结束标记。 |
| setNamespace(prefix: string, namespace: string): void | 写入当前元素标记的命名空间。 |
| setCommnet(text: string): void | 写入comment属性。 |
| setCData(text: string): void | 写入CData属性。 |
| setText(text: string): void | 写入Text属性。 |
| setDocType(text: string): void | 写入DocType属性。 |
| XmlPullParser(buffer: ArrayBuffer \| DataView, encoding?: string) | 创建并返回一个XmlPullParser对象，该XmlPullParser对象传参两个第一参数是ArrayBuffer或DataView一段内存，第二个参数为文件格式（默认为UTF-8）。 |
| parse(option: ParseOptions): void | 该接口用于解析xml，ParseOptions参数为一个接口包含五个可选参{supportDoctype?: boolea ignoreNameSpace?: boolean tagValueCallbackFunction?: (name: string, value: string) => boolean attributeValueCallbackFunction?: (name: string, value: string) => boolean） tokenValueCallbackFunction?: (eventType: EventType, value: ParseInfo) => boolean }。其中tokenValueCallbackFunction回调函数的入参1是事件类型，入参2是包含getColumnNumber、getDepth等get属性的info接口，用户可通过info.getDepth()等方法来获取当前解析过程中的depth等信息。 |
| alloc(size: number, fill?: string \| Buffer \| number, encoding?: BufferEncoding): Buffer | 创建size个字节长度的Buffer实例，并初始化。 |
| allocUninitializedFromPool(size: number): Buffer | 创建指定大小的未被初始化Buffer实例。内存从缓冲池分配。 创建的Buffer的内容未知，需要使用fill()函数来初始化Buffer实例。 |
| allocUninitialized(size: number): Buffer | 创建指定大小的未被初始化Buffer实例。内存不从缓冲池分配。 |
| byteLength(string: string \| Buffer \| TypedArray \| DataView \| ArrayBuffer \| SharedArrayBuffer, encoding?: BufferEncoding): number | 根据不同的编码方法，返回字符串的字节数。 |
| compare(buf1: Buffer \| Uint8Array, buf2: Buffer \| Uint8Array): -1 \| 0 \| 1 | 返回比较buf1和buf2的结果, 通常用于对Buffer实例的数组进行排序。 |
| concat(list: Buffer[] \| Uint8Array[], totalLength?: number): Buffer | 将list中的实例内容复制totalLength字节长度到新的Buffer实例中并返回。 |
| from(array: number[]): Buffer | 根据指定数组创建新的Buffer实例。 |
| from(arrayBuffer: ArrayBuffer \| SharedArrayBuffer, byteOffset?: number, length?: number): Buffer | 创建指定长度的与arrayBuffer共享内存的Buffer实例 |
| from(buffer: Buffer \| Uint8Array): Buffer | 创建并复制buffer数据到新的Buffer实例并返回。 |
| from(object: Object, offsetOrEncoding: number \| string, length: number): Buffer | 根据指定的object类型数据，创建新的Buffer实例。 |
| from(string: String, encoding?: BufferEncoding): Buffer | 根据指定编码格式的字符串，创建新的Buffer实例。 |
| isBuffer(obj: Object): boolean | 判断obj是否为Buffer。 |
| isEncoding(encoding: string):boolean | 判断encoding是否为支持的编码格式。 |
| transcode(source: Buffer \| Uint8Array, fromEnc: string, toEnc: string): Buffer | 将给定的Buffer或Uint8Array实例从一种字符编码重新编码为另一种。 |
| length: number | buffer的字节长度。 |
| buffer: ArrayBuffer | ArrayBuffer对象。 |
| byteOffset: number | 当前buffer所在内存池的偏移量。 |
| fill(value: string \| Buffer \| Uint8Array \| number, offset?: number, end?: number, encoding?: BufferEncoding): Buffer | 用value填充this实例指定位置的数据，默认为循环填充，并返回填充后的Buffer实例。 |
| compare(target: Buffer \| Uint8Array, targetStart?: number, targetEnd?: number, sourceStart?: number, sourceEnd?: number): -1 \| 0 \| 1 | this实例对象与target实例对象进行比较，返回buf在排序中的顺序，-1:前排序，0:与buf相同，1:后排序。 |
| copy(target: Buffer \| Uint8Array, targetStart?: number, sourceStart?: number, sourceEnd?: number): number | 将this实例中指定位置的数据复制到target的指定位置上，并返回复制的字节总长度。 |
| equals(otherBuffer: Uint8Array \| Buffer): boolean | 比较this实例和otherBuffer实例是否相等。 |
| includes(value: string \| number \| Buffer \| Uint8Array, byteOffset?: number, encoding?: BufferEncoding): boolean | 检查Buffer对象是否包含value值。 |
| indexOf(value: string \| number \| Buffer \| Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number | 查找this实例中第一次出现value的索引，如果不包含value，则为-1。 |
| keys(): IterableIterator<number> | 返回一个包含key值的迭代器。 |
| values(): IterableIterator<number> | 返回一个包含value的迭代器。 |
| entries(): IterableIterator<[number, number]> | 返回一个包含key和value的迭代器。 |
| lastIndexOf(value: string | number | Buffer | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number | 返回this实例中最后一次出现value的索引，如果对象不包含，则为-1。 |
| readBigInt64BE(offset?: number): bigint | 从指定的offset处读取有符号的大端序64位整数。 |
| readBigInt64LE(offset?: number): bigint | 从指定的offset处读取有符号的小端序64位整数。 |
| readBigUInt64BE(offset?: number): bigint | 从指定的offset处读取无符号的大端序64位整数。 |
| readBigUInt64LE(offset?: number): bigint | 从指定的offset处读取无符号的小端序64位整数。 |
| readDoubleBE(offset?: number): number | 从指定offset处读取64位大端序双精度值。 |
| readDoubleLE(offset?: number): number | 从指定offset处读取64位小端序双精度值。 |
| readFloatBE(offset?: number): number | 从指定offset处读取32位大端序浮点数。 |
| readFloatLE(offset?: number): number | 从指定offset处读取32位小端序浮点数。 |
| readInt8(offset?: number): number | 从指定的offset处读取有符号的8位整数。 |
| readInt16BE(offset?: number): number | 从指定的offset处读取有符号的大端序16位整数。 |
| readInt16LE(offset?: number): number | 从指定的offset处读取有符号的小端序16位整数。 |
| readInt32BE(offset?: number): number | 从指定的offset处读取有符号的大端序32位整数。 |
| readInt32LE(offset?: number): number | 从指定的offset处读取有符号的小端序32位整数。 |
| readIntBE(offset: number, byteLength: number): number | 从指定的offset处的buf读取byteLength个字节，并将结果解释为支持最高48位精度的大端序、二进制补码有符号值。 |
| readIntLE(offset: number, byteLength: number): number | 从指定的offset处的buf读取byteLength个字节，并将结果解释为支持最高48位精度的小端序、二进制补码有符号值。 |
| readUInt8(offset?: number): number | 从offset处读取8位无符号整型数。 |
| readUInt16BE(offset?: number): number | 从指定的`offset`处的buf读取无符号的大端序16位整数。 |
| readUInt16LE(offset?: number): number | 从指定的`offset`处的buf读取无符号的小端序16位整数。 |
| readUInt32BE(offset?: number): number | 从指定的`offset`处的buf读取无符号的大端序32位整数。 |
| readUInt32LE(offset?: number): number | 从指定的`offset`处的buf读取无符号的小端序32位整数。 |
| readUIntBE(offset: number, byteLength: number): number | 从指定的`offset`处的buf读取`byteLength`个字节，并将结果解释为支持最高48位精度的无符号大端序整数。 |
| readUIntLE(offset: number, byteLength: number): number | 从指定的`offset`处的buf读取`byteLength`个字节，并将结果解释为支持最高48位精度的无符号小端序整数。 |
| subarray(start?: number, end?: number): Buffer | 截取指定位置的`this`实例并返回。 |
| swap16(): Buffer | 将`this`实例解释为无符号的16位整数数组，并就地交换字节顺序。 |
| swap32(): Buffer | 将`this`实例解释为无符号的32位整数数组，并就地交换字节顺序。 |
| swap64(): Buffer | 将`this`实例解释为无符号的64位整数数组，并就地交换字节顺序。 |
| toJSON(): Object | 将buf转为JSON并返回。 |
| toString(encoding?: string, start?: number, end?: number): string | 将`this`实例中指定位置数据转成指定编码格式字符串并返回。 |
| write(str: string, offset?: number, length?: number, encoding?: string): number | 从buf的offset偏移写入指定编码的字符串str,写入的字节长度为length。 |
| writeBigInt64BE(value: bigint, offset?: number): number | 从buf的offset偏移写入有符号的大端序64位BigInt型数据value。 |
| writeBigInt64LE(value: bigint, offset?: number): number | 从buf的offset偏移写入有符号的小端序64位BigInt型数据value。 |
| writeBigUInt64BE(value: bigint, offset?: number): number | 从buf的offset偏移写入无符号的大端序64位BigUInt型数据value。 |
| writeBigUInt64LE(value: bigint, offset?: number): number | 从buf的offset偏移写入无符号的小端序64位BigUInt型数据value。 |
| writeDoubleBE(value: number, offset?: number): number | 从buf的offset偏移写入大端序的64位双浮点型数据value。 |
| writeDoubleLE(value: number, offset?: number): number | 从buf的offset偏移写入小端序的64位双浮点型数据value。 |
| writeFloatBE(value: number, offset?: number): number | 从buf的offset偏移写入大端序的32位浮点型数据value。 |
| writeFloatLE(value: number, offset?: number): number | 从buf的offset偏移写入小端序的32位浮点型数据value。 |
| writeInt8(value: number, offset?: number): number | 从buf的offset偏移写入8位有符号整型数据value。 |
| writeInt16BE(value: number, offset?: number): number | 从buf的offset偏移写入大端序的16位有符号整型数据value。 |
| writeInt16LE(value: number, offset?: number): number | 从buf的offset偏移写入小端序的16位有符号整型数据value。 |
| writeInt32BE(value: number, offset?: number): number | 从buf的offset偏移写入大端序的32位有符号整型数据value。 |
| writeInt32LE(value: number, offset?: number): number | 从buf的offset偏移写入小端序的32位有符号整型数据value。 |
| writeIntBE(value: number, offset: number, byteLength: number): number | 从buf的offset偏移写入大端序的有符号value数据,value字节长度为byteLength。 |
| writeIntLE(value: number, offset: number, byteLength: number): number | 从buf的offset偏移写入小端序的有符号value数据,value字节长度为byteLength。 |
| writeUInt8(value: number, offset?: number): number | 从buf的offset偏移写入8位无符号整型数据value。 |
| writeUInt16BE(value: number, offset?: number): number | 从buf的offset偏移写入大端序的16位无符号整型数据value。 |
| writeUInt16LE(value: number, offset?: number): number | 从buf的offset偏移写入小端序的16位无符号整型数据value。 |
| writeUInt32BE(value: number, offset?: number): number | 从buf的offset偏移写入大端序的32位无符号整型数据value。 |
| writeUInt32LE(value: number, offset?: number): number | 从buf的offset偏移写入小端序的32位无符号整型数据value。 |
| writeUIntBE(value: number, offset: number, byteLength: number): number | 从buf的offset偏移写入大端序的无符号value数据,value字节长度为byteLength。 |
| writeUIntLE(value: number, offset: number, byteLength: number): number | 从buf的offset偏移写入小端序的无符号value数据,value字节长度为byteLength。 |
| new Blob(sources: string[] \| ArrayBuffer[] \| TypedArray[] \| DataView[] \| Blob[] , options?: Object) | Blob的构造函数,返回一个Blob的实例对象。 |
| size | Blob实例的总字节大小。 |
| type | Blob实例的内容类型。 |
| arrayBuffer(): Promise&lt;ArrayBuffer&gt; | 将Blob中的数据放入到ArrayBuffer中，并返回一个Promise。 |
| slice(start?: number, end?: number, type?: string): Blob | 创建并返回一个复制原blob对象中start到end位置数据的新blob实例对象。 |
| text(): Promise&lt;string&gt; | 返回一个Promise，该Promise中的值为UTF8编码类型的文本。 |
#### 1.3.2. 使用说明 |

各接口使用方法如下：


1、new URL(url: string,base?:string|URL)
```
let b = new URL('https://developer.mozilla.org'); // => 'https://developer.mozilla.org/'

let a = new URL( 'sca/./path/path/../scasa/text', 'http://www.example.com');
// => 'http://www.example.com/sca/path/scasa/text'
```
2、tostring():string
```
const url = new URL('http://10.0xFF.O400.235:8080/directory/file?query#fragment');
url.toString() // => 'http://10.0xff.o400.235:8080/directory/file?query#fragment'

const url = new URL("http://[FEDC:BA98:7654:3210:FEDC:BA98:7654:3210]:80/index.html");
url.toString() // => 'http://[fedc:ba98:7654:3210:fedc:ba98:7654:3210]/index.html'

const url = new URL("http://username:password@host:8080/directory/file?query#fragment");
url.toString() // => 'http://username:password@host:8080/directory/file?query#fragment'
```
3、toJSON():string
```
const url = new URL("https://developer.mozilla.org/en-US/docs/Web/API/URL/toString");
url.toJSON(); // =>  'https://developer.mozilla.org/en-US/docs/Web/API/URL/toString'
```
4、new URLSearchParams()
```
let params = new URLSearchParams('foo=1&bar=2');
```
5、new URLSearchParams(string)
```
params = new URLSearchParams('user=abc&query=xyz');
console.log(params.get('user'));
// Prints 'abc'
```
6、new URLSearchParams(obj)
```
const params = new URLSearchParams({
    user: 'abc',
    query: ['first', 'second']
});
console.log(params.getAll('query'));
// Prints [ 'first,second' ]
```
7、new URLSearchParams(iterable)
```
let params;

// Using an array
params = new URLSearchParams([
    ['user', 'abc'],
    ['query', 'first'],
    ['query', 'second'],
]);
console.log(params.toString());
// Prints 'user = abc & query = first&query = second'
```
8、has(name: string): boolean
```
console.log(params.has('bar')); // =>true
```
9、set(name: string, value string): void
```
params.set('baz', 3);
```
10、sort(): void
```
params .sort();
```
11、toString(): string
```
console.log(params .toString()); // =>bar=2&baz=3&foo=1'
```
12、keys(): iterableIterator\<string>
```
for(var key of params.keys()) {
  console.log(key);
} // =>bar  baz  foo
```
13、values(): iterableIterator\<string>
```
for(var value of params.values()) {
  console.log(value);
} // =>2  3  1
```
14、append(name: string, value: string): void
```
params.append('foo', 3); // =>bar=2&baz=3&foo=1&foo=3
```
15、delete(name: string): void
```
params.delete('baz'); // => bar=2&foo=1&foo=3
```
16、get(name: string): string
```
params.get('foo'); // => 1
```
17、getAll(name: string): string[]
```
params.getAll('foo'); // =>[ '1', '3' ]
```
18、entries(): iterableIterator<[string, string]>
```
for(var pair of searchParams.entries()) {
   console.log(pair[0]+ ', '+ pair[1]);
} // => bar, 2   foo, 1  foo, 3
```
19、forEach(): void
```
url.searchParams.forEach((value, name, searchParams) => {
  console.log(name, value, url.searchParams === searchParams);
});
// => foo 1 true
// => bar 2 true
```
20、urlSearchParams[Symbol.iterator] ()
```
const params = new URLSearchParams('foo=bar&xyz=baz');
for (const [name, value] of params) {
    console.log(name, value);
}
// Prints:
// foo bar
// xyz bar
```


21、URI​(str: string)
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
```
22、scheme
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.scheme        // => "http";
```
23、authority
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.authority     // => "gg:gaogao@www.baidu.com:99";
```
24、ssp
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.ssp "         // => gg:gaogao@www.baidu.com:99/path/path?query";
```
25、userinfo
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.userinfo      // => "gg:gaogao";
```
26、host
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.host          // => "www.baidu.com";
```
27、port
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.port          // => "99";
```
28、query
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.query         // => "query";
```
29、fragment
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.fragment      // => "fagment";
```
30、path
```
let gaogao = new Uri.URI('http://gg:gaogao@www.baidu.com:99/path/path?query#fagment');
gaogao.path          // => "/path/path";
```
31、equals(ob: Object)
```
let gaogao = new Uri.URI('http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/path1?query#fagment');
let gaogao1 = gaogao;
let res = gaogao.equals(gaogao1);
console.log(res);      // => true;
```
32、normalize​()
```
let gaogao = new Uri.URI('http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/path/66./../././mm/.././path1?query#fagment');
let res = gaogao.normalize();
console.log(res.path);        // => "/path/path1"
console.log(res.toString());  // => "http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/path/path1?query#fagment"
```
33、checkIsAbsolute​()
```
let gaogao = new Uri.URI('f/tp://username:password@www.baidu.com:88/path?query#fagment');
let res = gaogao.checkIsAbsolute();
console.log(res);              //=> false;
```
34、toString()
```
let gaogao = new Uri.URI('http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/../../path/.././../aa/bb/cc?query#fagment');
let res = gaogao.toString();
console.log(res.toString());     // => 'http://gg:gaogao@[1:0:0:1:2:1:2:1]:99/../../path/.././../aa/bb/cc?query#fagment';
```


35、ConvertXml()
```
var convertml = new convertXml.ConvertXml();
```
36、convert(xml: string, options: Object)
```
var result = convertml.convert(xml, {compact: false, spaces: 4});
```
37、new XmlSerializer(buffer: ArrayBuffer | DataView, encoding?: string)
```

var arrayBuffer = new ArrayBuffer(1024);
var bufView = new DataView(arrayBuffer);
var thatSer = new xml.XmlSerializer(bufView);
```
38、setDeclaration()：void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setDeclaration() // => <?xml version="1.0" encoding="utf-8"?>;
```
39、setCommnet(text: string):void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setCommnet("Hello, World!"); // => <!--Hello, World!-->;
```
40、setCData(text: string) :void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setDocType('root SYSTEM "http://www.test.org/test.dtd"'); // => <![CDATA[root SYSTEM \“http://www.test.org/test.dtd\”]]>
```
41、setDocType(text: string):void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setDocType("foo"); // => <!DOCTYPE foo>
```
42、setNamespace(prefix: string, namespace: string): void
43、startElement(name: string): void
44、setAttributes(name: string, value: string): void
45、endElement(): void
46、setText(text: string): void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.setNamespace("h", "http://www.w3.org/TR/html4/");
thatSer.startElement("table");
thatSer.setAttributes("importance", "high");
thatSer.setText("Happy");
endElement(); // => <h:table importance="high" xmlns:h="http://www.w3.org/TR/html4/">Happy</h:table>
```
47、addEmptyElement(name: string): void
```
var thatSer = new xml.XmlSerializer(bufView);
thatSer.addEmptyElement("b"); // => <b/>
```
48、new (buffer: ArrayBuffer | DataView, encoding?: string)
```
var strXml =
            '<?xml version="1.0" encoding="utf-8"?>' +
            '<note importance="high" logged="true">' +
            '    <title>Happy</title>' +
            '</note>';
var arrayBuffer = new ArrayBuffer(strXml.length*2);
var bufView = new Uint8Array(arrayBuffer);
var strLen = strXml.length;
for (var i = 0; i < strLen; ++i) {
    bufView[i] = strXml.charCodeAt(i);//设置arraybuffer 方式
}
var that = new xml.XmlPullParser(arrayBuffer);

```
49、parse(option: ParseOptions): void
```
var strXml =
            '<?xml version="1.0" encoding="utf-8"?>' +
            '<note importance="high" logged="true">' +
            '    <title>Happy</title>' +
            '</note>';
var arrayBuffer = new ArrayBuffer(strXml.length*2);
var bufView = new Uint8Array(arrayBuffer);
var strLen = strXml.length;
for (var i = 0; i < strLen; ++i) {
    bufView[i] = strXml.charCodeAt(i);
}
var that = new xml.XmlPullParser(arrayBuffer);
var arrTag = {};
arrTag[0] = '132';
var i = 1;
function func(key, value){
    arrTag[i] = 'key:'+key+' value:'+ value.getDepth();
    i++;
    return true;
}
var options = {supportDoctype:true, ignoreNameSpace:true, tokenValueCallbackFunction:func}
that.parse(options);
```
50、alloc(size: number, fill?: string | Buffer | number, encoding?: BufferEncoding): Buffer
```
import buffer from '@ohos.buffer';

let buf1 = buffer.alloc(5);
let buf2 = buffer.alloc(5, 'a');
let buf3 = buffer.alloc(11, 'aGVsbG8gd29ybGQ=', 'base64');
```
51、allocUninitializedFromPool(size: number): Buffer
```
import buffer from '@ohos.buffer';

let buf = buffer.allocUninitializedFromPool(10);
buf.fill(0);
```
52、allocUninitialized(size: number): Buffer
```
import buffer from '@ohos.buffer';

let buf = buffer.allocUninitialized(10);
buf.fill(0);
```
53、byteLength(string: string | Buffer | TypedArray | DataView | ArrayBuffer | SharedArrayBuffer, encoding?: BufferEncoding): number
```
import buffer from '@ohos.buffer';

let str = '\u00bd + \u00bc = \u00be';
console.log(`${str}: ${str.length} characters, ${buffer.byteLength(str, 'utf-8')} bytes`);
// 打印: ½ + ¼ = ¾: 9 characters, 12 bytes
```
54、compare(buf1: Buffer | Uint8Array, buf2: Buffer | Uint8Array): -1 | 0 | 1
```
import buffer from '@ohos.buffer';

let buf1 = buffer.from('1234');
let buf2 = buffer.from('0123');
let res = buf1.compare(buf2);

console.log(Number(res).toString()); // 打印 1
```
55、concat(list: Buffer[] | Uint8Array[], totalLength?: number): Buffer
```
import buffer from '@ohos.buffer';

let buf1 = buffer.from("1234");
let buf2 = buffer.from("abcd");
let buf = buffer.concat([buf1, buf2]);
console.log(buf.toString('hex')); // 3132333461626364
```
56、from(array: number[]): Buffer
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0x62, 0x75, 0x66, 0x66, 0x65, 0x72]);
console.log(buf.toString('hex')); // 627566666572
```
57、from(arrayBuffer: ArrayBuffer | SharedArrayBuffer, byteOffset?: number, length?: number): Buffer
```
let ab = new ArrayBuffer(10);
let buf = buffer.from(ab, 0, 2);
```
58、from(buffer: Buffer | Uint8Array): Buffer
```
import buffer from '@ohos.buffer';

let buf1 = buffer.from('buffer');
let buf2 = buffer.from(buf1);
```
59、from(object: Object, offsetOrEncoding: number | string, length: number): Buffer
```
import buffer from '@ohos.buffer';

let buf = buffer.from(new String('this is a test'));
```
60、from(string: String, encoding?: BufferEncoding): Buffer
```
import buffer from '@ohos.buffer';

let buf1 = buffer.from('this is a test');
let buf2 = buffer.from('7468697320697320612074c3a97374', 'hex');

console.log(buf1.toString());	// 打印: this is a test
console.log(buf2.toString());
```
61、isBuffer(obj: Object): boolean
```
import buffer from '@ohos.buffer';

buffer.isBuffer(buffer.alloc(10)); // true
buffer.isBuffer(buffer.from('foo')); // true
buffer.isBuffer('a string'); // false
buffer.isBuffer([]); // false
buffer.isBuffer(new Uint8Array(1024)); // false
```
62、isEncoding(encoding: string):boolean
```
import buffer from '@ohos.buffer';

console.log(buffer.isEncoding('utf-8').toString());	// 打印: true
console.log(buffer.isEncoding('hex').toString());	// 打印: true
console.log(buffer.isEncoding('utf/8').toString());	// 打印: false
console.log(buffer.isEncoding('').toString());	// 打印: false
```
63、transcode(source: Buffer | Uint8Array, fromEnc: string, toEnc: string): Buffer
```
import buffer from '@ohos.buffer';

let buf = buffer.alloc(50);
let newBuf = buffer.transcode(buffer.from('€'), 'utf-8', 'ascii');
console.log(newBuf.toString('ascii'));
```
64、length: number
```
import buffer from '@ohos.buffer';

let buf = buffer.from("1236");
console.log(JSON.stringify(buf.length));
```
65、buffer: ArrayBuffer
```
import buffer from '@ohos.buffer';

let buf = buffer.from("1236");
let arrayBuffer = buf.buffer;
console.log(JSON.stringify(new Uint8Array(arrayBuffer)));
```
66、byteOffset: number
```
import buffer from '@ohos.buffer';

let buf = buffer.from("1236");
console.log(JSON.stringify(buf.byteOffset));
```
67、fill(value: string | Buffer | Uint8Array | number, offset?: number, end?: number, encoding?: BufferEncoding): Buffer
```
import buffer from '@ohos.buffer';

let b = buffer.allocUninitializedFromPool(50).fill('h');
console.log(b.toString());
```
68、compare(target: Buffer | Uint8Array, targetStart?: number, targetEnd?: number, sourceStart?: number, sourceEnd?: number): -1 | 0 | 1
```
import buffer from '@ohos.buffer';

let buf1 = buffer.from([1, 2, 3, 4, 5, 6, 7, 8, 9]);
let buf2 = buffer.from([5, 6, 7, 8, 9, 1, 2, 3, 4]);

console.log(buf1.compare(buf2, 5, 9, 0, 4).toString());	// 打印: 0
console.log(buf1.compare(buf2, 0, 6, 4).toString());	// 打印: -1
console.log(buf1.compare(buf2, 5, 6, 5).toString());	// 打印: 1
```
69、copy(target: Buffer | Uint8Array, targetStart?: number, sourceStart?: number, sourceEnd?: number): number
```
import buffer from '@ohos.buffer';

let buf1 = buffer.allocUninitializedFromPool(26);
let buf2 = buffer.allocUninitializedFromPool(26).fill('!');

for (let i = 0; i < 26; i++) {
  buf1[i] = i + 97;
}

buf1.copy(buf2, 8, 16, 20);
console.log(buf2.toString('ascii', 0, 25));
// 打印: !!!!!!!!qrst!!!!!!!!!!!!!
```
70、equals(otherBuffer: Uint8Array | Buffer): boolean
```
import buffer from '@ohos.buffer';

let buf1 = buffer.from('ABC');
let buf2 = buffer.from('414243', 'hex');
let buf3 = buffer.from('ABCD');

console.log(buf1.equals(buf2).toString());	// 打印: true
console.log(buf1.equals(buf3).toString());	// 打印: false
```
71、includes(value: string | number | Buffer | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): boolean
```
import buffer from '@ohos.buffer';

let buf = buffer.from('this is a buffer');
console.log(buf.includes('this').toString());	// 打印: true
console.log(buf.includes('be').toString());	// 打印: false
```
72、indexOf(value: string | number | Buffer | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from('this is a buffer');
console.log(buf.indexOf('this').toString());	// 打印: 0
console.log(buf.indexOf('is').toString());		// 打印: 2
```
73、keys(): IterableIterator\<number>
```
import buffer from '@ohos.buffer';

let buf = buffer.from('buffer');
for (const key of buf.keys()) {
  console.log(key.toString());
}
```
74、values(): IterableIterator\<number>
```
import buffer from '@ohos.buffer';

let buf1 = buffer.from('buffer');
for (let value of buf1.values()) {
  console.log(value.toString());
}
```
75、entries(): IterableIterator<[number, number]>
```
import buffer from '@ohos.buffer';

let buf = buffer.from('buffer');
for (let pair of buf.entries()) {
  console.log(pair.toString());
}
```
76、lastIndexOf(value: string | number | Buffer | Uint8Array, byteOffset?: number, encoding?: BufferEncoding): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from('this buffer is a buffer');
console.log(buf.lastIndexOf('this').toString());	// 打印: 0
console.log(buf.lastIndexOf('buffer').toString());	// 打印: 17
```
77、readBigInt64BE(offset?: number): bigint
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x70,
        0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78]);
console.log(buf.readBigInt64BE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(8);
buf1.writeBigInt64BE(0x0102030405060708n, 0);
```
78、readBigInt64LE(offset?: number): bigint
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x70,
        0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78]);
console.log(buf.readBigInt64LE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(8);
buf1.writeBigInt64BE(0x0102030405060708n, 0);
```
79、readBigUInt64BE(offset?: number): bigint
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x70,
        0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78]);
console.log(buf.readBigUInt64BE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(8);
buf1.writeBigUInt64BE(0xdecafafecacefaden, 0);
```
80、readBigUInt64LE(offset?: number): bigint
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x70,
        0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78]);
console.log(buf.readBigUInt64LE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(8);
buf1.writeBigUInt64BE(0xdecafafecacefaden, 0);
```
81、readDoubleBE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([1, 2, 3, 4, 5, 6, 7, 8]);
console.log(buf.readDoubleBE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(8);
buf1.writeDoubleBE(123.456, 0);
```
82、readDoubleLE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([1, 2, 3, 4, 5, 6, 7, 8]);
console.log(buf.readDoubleLE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(8);
buf1.writeDoubleLE(123.456, 0);
```
83、readFloatBE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([1, 2, 3, 4, 5, 6, 7, 8]);
console.log(buf.readFloatBE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(4);
buf1.writeFloatBE(0xcabcbcbc, 0);
```
84、readFloatLE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([1, 2, 3, 4, 5, 6, 7, 8]);
console.log(buf.readFloatLE(0).toString());

let buf1 = buffer.allocUninitializedFromPool(4);
buf1.writeFloatLE(0xcabcbcbc, 0);
```
85、readInt8(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([-1, 5]);
console.log(buf.readInt8(0).toString());	// 打印: -1
console.log(buf.readInt8(1).toString());	// 打印: 5

let buf1 = buffer.allocUninitializedFromPool(2);
buf1.writeInt8(0x12);
```
86、readInt16BE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0, 5]);
console.log(buf.readInt16BE(0).toString());	// 打印: 5

let buf1 = buffer.alloc(2);
buf1.writeInt16BE(0x1234, 0);
```
87、readInt16LE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0, 5]);
console.log(buf.readInt16LE(0).toString());	// 打印: 1280

let buf1 = buffer.alloc(2);
buf1.writeInt16BE(0x1234, 0);
```
88、readInt32BE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0, 0, 0, 5]);
console.log(buf.readInt32BE(0).toString());	// 打印: 5

let buf1 = buffer.alloc(4);
buf1.writeInt32BE(0x12345678, 0);
```
89、readInt32LE(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0, 0, 0, 5]);
console.log(buf.readInt32LE(0).toString());	// 打印: 83886080

let buf1 = buffer.alloc(4);
buf1.writeInt32BE(0x12345678, 0);
```
90、readIntBE(offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from("ab");
let num = buf.readIntBE(0, 1);
console.log(num.toString()); // 97

let buf1 = buffer.allocUninitializedFromPool(6);
buf1.writeIntBE(0x123456789011, 0, 6);
```
91、readIntLE(offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]);
console.log(buf.readIntLE(0, 6).toString(16));

let buf1 = buffer.allocUninitializedFromPool(6);
buf1.writeIntLE(0x123456789011, 0, 6);
```
92、readUInt8(offset?: number): number
```
import buffer from '@ohos.buffer';

let buf = buffer.from([1, -2]);
console.log(buf.readUInt8(0).toString());
console.log(buf.readUInt8(1).toString());

let buf1 = buffer.allocUninitializedFromPool(4);
buf1.writeUInt8(0x42);
```
93、readUInt16BE(offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.from([0x12, 0x34, 0x56]);
console.log(buf.readUInt16BE(0).toString(16));
console.log(buf.readUInt16BE(1).toString(16));
```
94、readUInt16LE(offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.from([0x12, 0x34, 0x56]);
console.log(buf.readUInt16LE(0).toString(16));
console.log(buf.readUInt16LE(1).toString(16));
```
95、readUInt32BE(offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.from([0x12, 0x34, 0x56, 0x78]);
console.log(buf.readUInt32BE(0).toString(16));
```
96、readUInt32LE(offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.from([0x12, 0x34, 0x56, 0x78]);
console.log(buf.readUInt32LE(0).toString(16));
```
97、readUIntBE(offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]);
console.log(buf.readUIntBE(0, 6).toString(16));
```
98、readUIntLE(offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.from([0x12, 0x34, 0x56, 0x78, 0x90, 0xab]);
console.log(buf.readUIntLE(0, 6).toString(16));
```
99、subarray(start?: number, end?: number): Buffer
```
import buffer from '@ohos.buffer';
let buf1 = buffer.allocUninitializedFromPool(26);
for (let i = 0; i < 26; i++) {
  buf1[i] = i + 97;
}
const buf2 = buf1.subarray(0, 3);
console.log(buf2.toString('ascii', 0, buf2.length));
```
100、swap16(): Buffer
```
import buffer from '@ohos.buffer';
let buf1 = buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]);
console.log(buf1.toString('hex'));
buf1.swap16();
console.log(buf1.toString('hex'));
```
101、swap32(): Buffer
```
import buffer from '@ohos.buffer';
let buf1 = buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]);
console.log(buf1.toString('hex'));
buf1.swap32();
console.log(buf1.toString('hex'));
```
102、swap64(): Buffer
```
import buffer from '@ohos.buffer';
let buf1 = buffer.from([0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8]);
console.log(buf1.toString('hex'));
buf1.swap64();
console.log(buf1.toString('hex'));
```
103、toJSON(): Object
```
import buffer from '@ohos.buffer';
let buf1 = buffer.from([0x1, 0x2, 0x3, 0x4, 0x5]);
let obj = buf1.toJSON();
console.log(JSON.stringify(obj))
```
104、toString(encoding?: string, start?: number, end?: number): string
```
import buffer from '@ohos.buffer';
let buf1 = buffer.allocUninitializedFromPool(26);
for (let i = 0; i < 26; i++) {
  buf1[i] = i + 97;
}
console.log(buf1.toString('utf-8'));
```
105、write(str: string, offset?: number, length?: number, encoding?: string): number
```
import buffer from '@ohos.buffer';
let buf = buffer.alloc(256);
let len = buf.write('\u00bd + \u00bc = \u00be', 0);
console.log(`${len} bytes: ${buf.toString('utf-8', 0, len)}`);
let buffer1 = buffer.alloc(10);
let length = buffer1.write('abcd', 8);
```
106、writeBigInt64BE(value: bigint, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeBigInt64BE(0x0102030405060708n, 0);
```
107、writeBigInt64LE(value: bigint, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeBigInt64LE(0x0102030405060708n, 0);
```
108、writeBigUInt64BE(value: bigint, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeBigUInt64BE(0xdecafafecacefaden, 0);
```
109、writeBigUInt64LE(value: bigint, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeBigUInt64LE(0xdecafafecacefaden, 0);
```
110、writeDoubleBE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeDoubleBE(123.456, 0);
```
111、writeDoubleLE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeDoubleLE(123.456, 0);
```
112、writeFloatBE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeFloatBE(0xcafebabe, 0);
```
113、writeFloatLE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(8);
buf.writeFloatLE(0xcafebabe, 0);
```
114、writeInt8(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(2);
buf.writeInt8(2, 0);
buf.writeInt8(-2, 1);
```
115、writeInt16BE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(2);
buf.writeInt16BE(0x0102, 0);
```
116、writeInt16LE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(2);
buf.writeInt16LE(0x0304, 0);
```
117、writeInt32BE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(4);
buf.writeInt32BE(0x01020304, 0);
```
118、writeInt32LE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(4);
buf.writeInt32LE(0x05060708, 0);
```
119、writeIntBE(value: number, offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(6);
buf.writeIntBE(0x1234567890ab, 0, 6);
```
120、writeIntLE(value: number, offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(6);
buf.writeIntLE(0x1234567890ab, 0, 6);
```
121、writeUInt8(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(4);
buf.writeUInt8(0x3, 0);
buf.writeUInt8(0x4, 1);
buf.writeUInt8(0x23, 2);
buf.writeUInt8(0x42, 3);
```
122、writeUInt16BE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(4);
buf.writeUInt16BE(0xdead, 0);
buf.writeUInt16BE(0xbeef, 2);
```
123、writeUInt16LE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(4);
buf.writeUInt16LE(0xdead, 0);
buf.writeUInt16LE(0xbeef, 2);
```
124、writeUInt32BE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(4);
buf.writeUInt32BE(0xfeedface, 0);
```
125、writeUInt32LE(value: number, offset?: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(4);
buf.writeUInt32LE(0xfeedface, 0);
```
126、writeUIntBE(value: number, offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(6);
buf.writeUIntBE(0x1234567890ab, 0, 6);
```
127、writeUIntLE(value: number, offset: number, byteLength: number): number
```
import buffer from '@ohos.buffer';
let buf = buffer.allocUninitializedFromPool(6);
buf.writeUIntLE(0x1234567890ab, 0, 6);
```
128、new Blob(sources: string[] | ArrayBuffer[] | TypedArray[] | DataView[] | Blob[] , options?: Object)
```
import buffer from '@ohos.buffer';
let blob = new buffer.Blob(['a', 'b', 'c']);
let blob1 = new buffer.Blob(['a', 'b', 'c'], {endings:'native', type: 'MIME'});
```
129、size
```
import buffer from '@ohos.buffer';
let blob = new buffer.Blob(['a', 'b', 'c']);
blob.size
```
130、type
```
import buffer from '@ohos.buffer';
let blob = new buffer.Blob(['a', 'b', 'c'], {endings:'native', type: 'MIME'});
blob.type
```
131、arrayBuffer(): Promise&lt;ArrayBuffer&gt;
```
let blob = new buffer.Blob(['a', 'b', 'c']);
let pro = blob.arrayBuffer();
pro.then(val => {
  let uintarr = new Uint8Array(val);
  console.log(uintarr.toString());
});
```
132、slice(start?: number, end?: number, type?: string): Blob
```
let blob = new buffer.Blob(['a', 'b', 'c']);
let blob2 = blob.slice(0, 2);
let blob3 = blob.slice(0, 2, "MIME");
```
133、text(): Promise&lt;string&gt;
```
let blob = new buffer.Blob(['a', 'b', 'c']);
let pro = blob.text();
pro.then(val => {
    console.log(val)
});
```

## 2. js_util_module子模块
### 2.1. 简介

UTIL接口用于字符编码TextEncoder、解码TextDecoder、帮助函数HelpFunction、基于Base64的字节编码encode和解码decode、有理数RationalNumber。TextEncoder表示一个文本编码器，接受字符串作为输入，以UTF-8格式进行编码，输出UTF-8字节流。TextDecoder接口表示一个文本解码器，解码器将字节流作为输入，输出stirng字符串。HelpFunction主要是对函数做callback化、promise化以及对错误码进行编写输出，及类字符串的格式化输出。encode接口使用Base64编码方案将指定u8数组中的所有字节编码到新分配的u8数组中或者使用Base64编码方案将指定的字节数组编码为String。decode接口使用Base64编码方案将Base64编码的字符串或输入u8数组解码为新分配的u8数组。RationalNumber有理数主要是对有理数进行比较，获取分子分母等方法。LruBuffer该算法在缓存空间不够的时候，将近期最少使用的数据替换为新数据。该算法源自这样一种访问资源的需求：近期访问的数据，可能在不久的将来会再次访问。于是最少访问的数据就是价值最小的，是最应该踢出缓存空间的数据。Scope接口用于描述一个字段的有效范围。 Scope实例的构造函数用于创建具有指定下限和上限的对象，并要求这些对象必须具有可比性。
### 2.2. 目录

```
commomlibrary/ets_utils/js_util_module/
├── Class:TextEncoder                   # TextEncoder类
│   ├──  new TextEncoder()              # 创建TextEncoder对象
│   ├──  encode()                       # encode方法
│   ├──  encoding                       # encoding属性
│   └──  encodeInto()                   # encodeInto方法
├── Class:TextDecoder                   # TextDecoder类
│   ├──  new TextDecoder()              # 创建TextDecoder对象
│   ├──  decode()                       # decode方法
|   ├──  decodeWithStream()             # decodeWithStream方法
│   ├──  encoding                       # encoding属性
│   ├──  fatal                          # fatal属性
│   └──  ignoreBOM                      # ignoreBOM属性
├── printf()                            # printf方法
├── getErrorString()                    # getErrorString方法
├── callbackWrapper()                   # callbackWrapper方法
├── promiseWrapper()                    # promiseWrapper方法
├── Class:Base64                        # Base64类
│   ├──  new Base64()                   # 创建Base64对象
│   ├──  encodeSync()                   # encodeSync方法
│   ├──  encodeToStringSync()           # encodeToStringSync方法
│   ├──  decodeSync()                   # decodeSync方法
│   ├──  encode()                       # encode方法
│   ├──  encodeToString()               # encodeToString方法
│   └──  decode()                       # decode方法
├── Class:RationalNumber                # RationalNumber类
│   ├──  new RationalNumber()           # 创建RationalNumber对象
│   ├──  createRationalFromString()     # createRationalFromString方法
│   ├──  compareTo()                    # compareTo方法
│   ├──  equals()                       # equals方法
│   ├──  valueOf()                      # valueOf方法
│   ├──  getCommonDivisor()             # getCommonDivisor方法
│   ├──  getDenominator()               # getDenominator方法
│   ├──  getNumerator()                 # getNumerator方法
│   ├──  isFinite()                     # isFinite方法
│   ├──  isNaN()                        # isNaN方法
│   ├──  isZero()                       # isZero方法
│   └──  toString()                     # toString方法
├── Class:LruBuffer                     # LruBuffer类
│   ├──  new LruBuffer()                # 创建LruBuffer对象
│   ├──  updateCapacity()               # updateCapacity方法
│   ├──  toString()                     # toString方法
│   ├──  values()                       # values方法
│   ├──  length                         # length属性
│   ├──  getCapacity()                  # getCapacity方法
│   ├──  clear()                        # clear方法
│   ├──  getCreateCount()               # getCreateCount方法
│   ├──  getMissCount()                 # getMissCount方法
│   ├──  getRemovalCount()              # getRemovalCount方法
│   ├──  getMatchCount()                # getMatchCount方法
│   ├──  getPutCount()                  # getPutCount方法
│   ├──  isEmpty()                      # isEmpty方法
│   ├──  get()                          # get方法
│   ├──  put()                          # put方法
│   ├──  keys()                         # keys方法
│   ├──  remove()                       # remove方法
│   ├──  afterRemoval()                 # afterRemoval方法
│   ├──  contains()                     # contains方法
│   ├──  createDefault()                # createDefault方法
│   ├──  entries()                      # entries方法
│   └──  [Symbol.iterator]()            # Symboliterator方法
|—— Class:Scope                         # Scope类
|   ├── constructor()                   # 创建Scope对象
|   ├── toString()                      # toString方法
|   ├── intersect()                     # intersect方法
|   ├── intersect()                     # intersect方法
|   ├── getUpper()                      # getUpper方法
|   ├── getLower()                      # getLower方法
|   ├── expand()                        # expand方法
|   ├── expand()                        # expand方法
|   ├── expand()                        # expand法
|   ├── contains()                      # contains方法
|   ├── contains()                      # contains方法
|   └── clamp()                         # clamp方法
|—— Class:Types                         # Types类
|   ├── isAnyArrayBuffer()              # isAnyArrayBuffer方法
|   ├── isArrayBufferView()             # isArrayBufferView方法
|   ├── isArgumentsObject()             # isArgumentsObject方法
|   ├── isArrayBuffer()                 # isArrayBuffer方法
|   ├── isAsyncFunction()               # isAsyncFunction方法
|   ├── isBigInt64Array()               # isBigInt64Array方法
|   ├── isBigUint64Array()              # isBigUint64Array方法
|   ├── isBooleanObject()               # isBooleanObject方法
|   ├── isBoxedPrimitive()              # isBoxedPrimitive方法
|   ├── isDataView()                    # isDataView方法
|   ├── isDate()                        # isDate方法
|   ├── isExternal()                    # isExternal方法
|   ├── isFloat32Array()                # isFloat32Array方法
|   ├── isFloat64Array()                # isFloat64Array方法
|   ├── isGeneratorFunction()           # isGeneratorFunction方法
|   ├── isGeneratorObject()             # isGeneratorObject方法
|   ├── isInt8Array()                   # isInt8Array方法
|   ├── isInt16Array()                  # isInt16Array方法
|   ├── isInt32Array()                  # isInt32Array方法
|   ├── isMap()                         # isMap方法
|   ├── isMapIterator()                 # isMapIterator方法
|   ├── isModuleNamespaceObject()       # isModuleNamespaceObject方法
|   ├── isNativeError()                 # isNativeError方法
|   ├── isNumberObject()                # isNumberObject方法
|   ├── isPromise()                     # isPromise方法
|   ├── isProxy()                       # isProxy方法
|   ├── isRegExp()                      # isRegExp方法
|   ├── isSet()                         # isSet方法
|   ├── isSetIterator()                 # isSetIterator方法
|   ├── isSharedArrayBuffer()           # isSharedArrayBuffer方法
|   ├── isStringObject()                # isStringObject方法
|   ├── isSymbolObject()                # isSymbolObject方法
|   ├── isTypedArray()                  # isTypedArray方法
|   ├── isUint8Array()                  # isUint8Array方法
|   ├── isUint8ClampedArray()           # isUint8ClampedArray方法
|   ├── isUint16Array()                 # isUint16Array方法
|   ├── isUint32Array()                 # isUint32Array方法
|   ├── isWeakMap()                     # isWeakMap方法
|   └── isWeakSet()                     # isWeakSet方法
|—— Class:ArrayList
|   ├── new ArrayList()                 # 创建ArrayList对象
|   ├── length                          # length属性
|   ├── add()                           # add方法
|   ├── insert()                        # insert方法
|   ├── has()                           # has方法
|   ├── getIndexOf()                    # getIndexOf方法
|   ├── removeByIndex()                 # removeByIndex方法
|   ├── remove()                        # remove方法
|   ├── getLastIndexOf()                # getLastIndexOf方法
|   ├── removeByRange()                 # removeByRange方法
|   ├── replaceAllElements()            # replaceAllElements方法
|   ├── forEach()                       # forEach方法
|   ├── sort()                          # sort方法
|   ├── subArrayList()                  # subArrayList方法
|   ├── clear()                         # clear方法
|   ├── clone()                         # clone方法
|   ├── getCapacity()                   # getCapacity方法
|   ├── convertToArray()                # convertToArray方法
|   ├── isEmpty()                       # isEmpty方法
|   ├── increaseCapacityTo()            # increaseCapacityTo方法
|   ├── trimToCurrentLength()           # trimToCurrentLength方法
|   └── isEmpty()                       # isEmpty方法
|—— Class:Deque
|   ├── new Deque()                     # 创建Deque对象
|   ├── length                          # length属性
|   ├── add()                           # add方法
|   ├── insertFront()                   # insertFront方法
|   ├── insertEnd()                     # insertEnd方法
|   ├── has()                           # has方法
|   ├── getFirst()                      # getFirst方法
|   ├── getLast()                       # getLast方法
|   ├── popFirst()                      # popFirst方法
|   ├── popLast()                       # popLast方法
|   └── forEach()                       # forEach方法
|—— Class:HashMap
|   ├── new HashMap()                   # 创建HashMap对象
|   ├── length                          # length属性
|   ├── isEmpty()                       # isEmpty方法
|   ├── hasKey()                        # hasKey方法
|   ├── hasValue()                      # hasValue方法
|   ├── setAll()                        # setAll方法
|   ├── set()                           # set方法
|   ├── remove()                        # remove方法
|   ├── clear()                         # clear方法
|   ├── keys()                          # keys方法
|   ├── values()                        # values方法
|   ├── replace()                       # replace方法
|   ├── forEach()                       # forEach方法
|   └── entries()                       # entries方法
|—— Class:HashSet
|   ├── new HashSet()                   # 创建HashSet对象
|   ├── length                          # length属性
|   ├── isEmpty()                       # isEmpty方法
|   ├── has()                           # has方法
|   ├── add()                           # add方法
|   ├── remove()                        # remove方法
|   ├── clear()                         # clear方法
|   ├── forEach()                       # forEach方法
|   ├── values()                        # values方法
|   └── entries()                       # entries方法
|—— Class:LightWeightMap
|   ├── new LightWeightMap()            # 创建LightWeightMap对象
|   ├── length                          # length属性
|   ├── hasAll()                        # hasAll方法
|   ├── hasKey()                        # hasKey方法
|   ├── hasValue()                      # hasValue方法
|   ├── increaseCapacityTo()            # increaseCapacityTo方法
|   ├── entries()                       # entries方法
|   ├── get()                           # get方法
|   ├── getIndexOfKey()                 # getIndexOfKey方法
|   ├── getIndexOfValue()               # getIndexOfValue方法
|   ├── isEmpty()                       # isEmpty方法
|   ├── getKeyAt()                      # getKeyAt方法
|   ├── keys()                          # keys方法
|   ├── setAll()                        # setAll方法
|   ├── set()                           # set方法
|   ├── remove()                        # remove方法
|   ├── removeAt()                      # removeAt方法
|   ├── clear()                         # clear方法
|   ├── setValueAt()                    # setValueAt方法
|   ├── forEach()                       # forEach方法
|   ├── toString()                      # toString方法
|   ├── getValueAt()                    # getValueAt方法
|   ├── values()                        # values方法
|   └── [Symbol.iterator]()             # [Symbol.iterator]方法
|—— Class:LightWeightSet
|   ├── new LightWeightSet()            # 创建LightWeightSet对象
|   ├── length                          # length属性
|   ├── add()                           # add方法
|   ├── addAll()                        # addAll方法
|   ├── hasAll()                        # hasAll方法
|   ├── has()                           # has方法
|   ├── equal()                         # equal方法
|   ├── increaseCapacityTo()            # increaseCapacityTo方法
|   ├── getIndexOf()                    # getIndexOf方法
|   ├── remove()                        # remove方法
|   ├── removeAt()                      # removeAt方法
|   ├── clear()                         # clear方法
|   ├── forEach()                       # forEach方法
|   ├── [Symbol.iterator]()             # [Symbol.iterator]方法
|   ├── toString()                      # toString方法
|   ├── toArray()                       # toArray方法
|   ├── getValueAt()                    # getValueAt方法
|   ├── values()                        # values方法
|   ├── entries()                       # entries方法
|   └── isEmpty()                       # isEmpty方法
|—— Class:LinkedList
|   ├── new LinkedList()                # 创建LinkedList对象
|   ├── length                          # length属性
|   ├── add()                           # add方法
|   ├── insert()                        # insert方法
|   ├── get()                           # get方法
|   ├── addFirst()                      # addFirst方法
|   ├── removeFirst()                   # removeFirst方法
|   ├── removeLast()                    # removeLast方法
|   ├── has()                           # has方法
|   ├── getIndexOf()                    # getIndexOf方法
|   ├── removeByIndex()                 # removeByIndex方法
|   ├── remove()                        # remove方法
|   ├── removeFirstFound()              # removeFirstFound方法
|   ├── removeLastFound()               # removeLastFound方法
|   ├── getLastIndexOf()                # getLastIndexOf方法
|   ├── getFirst()                      # getFirst方法
|   ├── getLast()                       # getLast方法
|   ├── set()                           # set方法
|   ├── forEach()                       # forEach方法
|   ├── clear()                         # clear方法
|   ├── clone()                         # clone方法
|   ├── convertToArray()                # convertToArray方法
|   └── [Symbol.iterator]()             # [Symbol.iterator]方法
|—— Class:List
|   ├── new List()                      # 创建List对象
|   ├── length                          # length属性
|   ├── add()                           # add方法
|   ├── insert()                        # insert方法
|   ├── get()                           # get方法
|   ├── has()                           # has方法
|   ├── getIndexOf()                    # getIndexOf方法
|   ├── removeByIndex()                 # removeByIndex方法
|   ├── remove()                        # remove方法
|   ├── getLastIndexOf()                # getLastIndexOf方法
|   ├── getFirst()                      # getFirst方法
|   ├── getLast()                       # getLast方法
|   ├── set()                           # set方法
|   ├── equal()                         # equal方法
|   ├── forEach()                       # forEach方法
|   ├── sort()                          # sort方法
|   ├── clear()                         # clear方法
|   ├── getSubList()                    # getSubList方法
|   ├── replaceAllElements()            # replaceAllElements方法
|   ├── convertToArray()                # convertToArray方法
|   ├── isEmpty()                       # isEmpty方法
|   └── [Symbol.iterator]()             # [Symbol.iterator]方法
|—— Class:PlainArray
|   ├── new PlainArray()                # 创建PlainArray对象
|   ├── length                          # length属性
|   ├── add()                           # add方法
|   ├── clear()                         # clear方法
|   ├── clone()                         # clone方法
|   ├── has()                           # has方法
|   ├── get()                           # get方法
|   ├── getIndexOfKey()                 # getIndexOfKey方法
|   ├── getIndexOfValue()               # getIndexOfValue方法
|   ├── isEmpty()                       # isEmpty方法
|   ├── getKeyAt()                      # getKeyAt方法
|   ├── remove()                        # remove方法
|   ├── removeAt()                      # removeAt方法
|   ├── removeRangeFrom()               # removeRangeFrom方法
|   ├── setValueAt()                    # setValueAt方法
|   ├── toString()                      # toString方法
|   ├── getValueAt()                    # getValueAt方法
|   ├── forEach()                       # forEach方法
|   └── [Symbol.iterator]()             # [Symbol.iterator]方法
|—— Class:Queue
|   ├── new Queue()                     # 创建Queue对象
|   ├── length                          # length属性
|   ├── add()                           # add方法
|   ├── getFirst()                      # getFirst方法
|   ├── pop()                           # pop方法
|   ├── forEach()                       # forEach方法
|   └── [Symbol.iterator]()             # [Symbol.iterator]方法
|—— Class:Stack
|   ├── new Stack()                     # 创建Stack对象
|   ├── length                          # length属性
|   ├── isEmpty()                       # isEmpty方法
|   ├── peek()                          # peek方法
|   ├── pop()                           # pop方法
|   ├── push()                          # push方法
|   ├── locate()                        # locate方法
|   ├── forEach()                       # forEach方法
|   └── [Symbol.iterator]()             # [Symbol.iterator]方法
|—— Class:TreeMap
|   ├── new TreeMap()                   # 创建TreeMap对象
|   ├── length                          # length属性
|   ├── isEmpty()                       # isEmpty方法
|   ├── hasKey()                        # hasKey方法
|   ├── hasValue()                      # hasValue方法
|   ├── get()                           # get方法
|   ├── getFirstKey()                   # getFirstKey方法
|   ├── getLastKey()                    # getLastKey方法
|   ├── setAll()                        # setAll方法
|   ├── set()                           # set方法
|   ├── remove()                        # remove方法
|   ├── clear()                         # clear方法
|   ├── getLowerKey()                   # getLowerKey方法
|   ├── getHigherKey()                  # getHigherKey方法
|   ├── keys()                          # keys方法
|   ├── values()                        # values方法
|   ├── replace()                       # replace方法
|   ├── forEach()                       # forEach方法
|   ├── entries()                       # entries方法
|   └── [Symbol.iterator]()             # [Symbol.iterator]方法
└── Class:TreeSet
    ├── new TreeSet()                   # 创建TreeSet对象
    ├── length                          # length属性
    ├── isEmpty()                       # isEmpty方法
    ├── has()                           # has方法
    ├── add()                           # add方法
    ├── remove()                        # remove方法
    ├── clear()                         # clear方法
    ├── getFirstValue()                 # getFirstValue方法
    ├── getLastValue()                  # getLastValue方法
    ├── getLowerValue()                 # getLowerValue方法
    ├── getHigherValue()                # getHigherValue方法
    ├── popFirst()                      # popFirst方法
    ├── popLast()                       # popLast方法
    ├── forEach()                       # forEach方法
    ├── values()                        # values方法
    ├── entries()                       # entries方法
    └── [Symbol.iterator]()             # [Symbol.iterator]方法
```

### 2.3. 说明

#### 2.3.1. 接口说明


| 接口名 | 说明 |
| -------- | -------- |
| constructor(encoding? : string) | 构造函数，参数encoding表示编码的格式。默认utf-8, 支持gb18030, gbk, gb2312. |
| readonly encoding : string | 在TextEncoder类中，获取编码的格式，只支持UTF-8。 |
| encode(input : string) : Uint8Array | 输入stirng字符串，根据encodeing编码并输出uint8字节流。 |
| encodeInto(input : string, dest : Uint8Array) : {read : number, written : number} | 输入stirng字符串，dest表示编码后存放位置，返回一个对象，read表示已经编码的字符的个数，written表示已编码字符所占字节的大小。 |
| constructor(encoding? : string, options? : {fatal? : boolean, ignoreBOM? : boolean}) | 构造函数，第一个参数encoding表示解码的格式。第二个参数表示一些属性。属性中fatal表示是否抛出异常，ignoreBOM表示是否忽略bom标志。 |
| readonly encoding : string | 在TextDecoder类中，获取设置的解码格式。 |
| readonly fatal : boolean | 获取抛出异常的设置。 |
| readonly ignoreBOM : boolean | 获取是否忽略bom标志的设置。 |
| decode(input : Uint8Array, options?: { stream?: false }) : string | 输入要解码的数据，解出对应的string字符串。第一个参数input表示要解码的数据，第二个参数options表示一个bool标志，表示将跟随附加数据，默认为false。 |
| decodeWithStream(input : Uint8Array, options?: { stream?: false }) : string | 输入要解码的数据，解出对应的string字符串。第一个参数input表示要解码的数据，第二个参数options表示一个bool标志，表示将跟随附加数据，默认为false。 |
| encodeSync(src: Uint8Array): Uint8Array; | 使用Base64编码方案将指定u8数组中的所有字节编码到新分配的u8数组中。 |
| encodeToStringSync(src: Uint8Array): string; | 使用Base64编码方案将指定的字节数组编码为String。 |
| decodeSync(src: Uint8Array \| string): Uint8Array; | 使用Base64编码方案将Base64编码的字符串或输入u8数组解码为新分配的u8数组。 |
| encode(src: Uint8Array): Promise\<Uint8Array\>; | 使用Base64编码方案将指定u8数组中的所有字节异步编码到新分配的u8数组中。 |
| encodeToString(src: Uint8Array): Promise\<string\>; | 使用Base64编码方案将指定的字节数组异步编码为String。 |
| decode(src: Uint8Array \| string): Promise\<Uint8Array\>; | 使用Base64编码方案将Base64编码的字符串或输入u8数组异步解码为新分配的u8数组。 |
| static createRationalFromString(rationalString: string): RationalNumber | 基于给定的字符串创建一个RationalNumber对象。 |
| compareTo(another: RationalNumber): number | 将当前的RationalNumber对象与给定的对象进行比较。 |
| equals(obj: object): number | 检查给定对象是否与当前 RationalNumber 对象相同。 |
| valueOf(): number | 将当前的RationalNumber对象进行取整数值或者浮点数值。 |
| static getCommonDivisor(number1: number, number2: number,): number | 获得两个指定数的最大公约数。 |
| getDenominator(): number | 获取当前的RationalNumber对象的分母。 |
| getNumerator(): number | 获取当前的RationalNumber对象的分子。 |
| isFinite(): boolean | 检查当前的RationalNumber对象是有限的。 |
| isNaN(): boolean | 检查当前RationalNumber对象是否表示非数字(NaN)值。 |
| isZero(): boolean | 检查当前RationalNumber对象是否表示零值。 |
| toString(): string | 获取当前RationalNumber对象的字符串表示形式。 |
| constructor(capacity?: number) | 创建默认构造函数用于创建一个新的LruBuffer实例，默认容量为64。 |
| updateCapacity(newCapacity: number): void | 将缓冲区容量更新为指定容量，如果 newCapacity 小于或等于 0，则抛出此异常。 |
| toString(): string | 返回对象的字符串表示形式，输出对象的字符串表示  |
| values(): V[] | 获取当前缓冲区中所有值的列表，输出按升序返回当前缓冲区中所有值的列表，从最近访问到最近最少访问。 |
| length: number | 代表当前缓冲区中值的总数，输出返回当前缓冲区中值的总数。 |
| getCapacity(): number | 获取当前缓冲区的容量，输出返回当前缓冲区的容量。 |
| clear(): void | 从当前缓冲区清除键值对，清除键值对后，调用afterRemoval()方法依次对其执行后续操作。 |
| getCreateCount(): number | 获取createDefault()返回值的次数,输出返回createDefault()返回值的次数。 |
| getMissCount(): number | 获取查询值不匹配的次数，输出返回查询值不匹配的次数。 |
| getRemovalCount(): number | 获取从缓冲区中逐出值的次数，输出从缓冲区中驱逐的次数。 |
| getMatchCount​(): number | 获取查询值匹配成功的次数，输出返回查询值匹配成功的次数。 |
| getPutCount(): number | 获取将值添加到缓冲区的次数，输出返回将值添加到缓冲区的次数。 |
| isEmpty(): boolean | 检查当前缓冲区是否为空，输出如果当前缓冲区不包含任何值，则返回 true 。 |
| get(key: K) : V \| undefined | 表示要查询的键，输出如果指定的键存在于缓冲区中，则返回与键关联的值；否则返回undefined。 |
| put(key: K , value: V): V | 将键值对添加到缓冲区，输出与添加的键关联的值；如果要添加的键已经存在，则返回原始值，如果键或值为空，则抛出此异常。 |
| keys(): K[ ] | 获取当前缓冲区中值的键列表，输出返回从最近访问到最近最少访问排序的键列表。 |
| remove​(key: K): V \| undefined |  从当前缓冲区中删除指定的键及其关联的值。 |
| afterRemoval(isEvict: boolean, key: K, value : V, newValue : V):void | 删除值后执行后续操作。 |
| contains(key: K): boolean | 检查当前缓冲区是否包含指定的键，输出如果缓冲区包含指定的键，则返回 true 。 |
| createDefault(key: K): V | 如果未计算特定键的值，则执行后续操作，参数表示丢失的键,输出返回与键关联的值。 |
| entries(): [K,V] | 允许迭代包含在这个对象中的所有键值对。每对的键和值都是对象。 |
| \[Symbol.iterator\](): [K,V] | 返回以键值对得形式得一个二维数组。 |
| constructor(lowerObj: ScopeType, upperObj : ScopeType) | 创建并返回一个Scope对象，用于创建指定下限和上限的作用域实例的构造函数。 |
| toString(): string | 该字符串化方法返回一个包含当前范围的字符串表示形式。 |
| intersect(range: Scope): Scope | 获取给定范围和当前范围的交集。 |
| intersect(lowerObj: ScopeType, upperObj: ScopeType): Scope | 获取当前范围与给定下限和上限范围的交集。 |
| getUpper(): ScopeType | 获取当前范围的上限。 |
| getLower(): ScopeType | 获取当前范围的下限。 |
| expand(lowerObj: ScopeType, upperObj:  ScopeType): Scope | 创建并返回包括当前范围和给定下限和上限的并集。 |
| expand(range: Scope): Scope | 创建并返回包括当前范围和给定范围的并集。 |
| expand(value: ScopeType): Scope | 创建并返回包括当前范围和给定值的并集。 |
| contains(value: ScopeType): boolean | 检查给定value是否包含在当前范围内。 |
| contains(range: Scope): boolean | 检查给定range是否在当前范围内。 |
| clamp(value: ScopeType): ScopeType | 将给定value限定到当前范围内。 |
| function printf(format: string, ...args: Object[]): string | printf()方法使用第一个参数作为格式字符串（其可以包含零个或多个格式说明符）来返回格式化的字符串。 |
| function getErrorString(errno: number): string | getErrorString()方法使用一个系统的错误数字作为参数，用来返回系统的错误信息。 |
| function callbackWrapper(original: Function): (err: Object, value: Object) => void | 参数为一个采用 async 函数（或返回 Promise 的函数）并返回遵循错误优先回调风格的函数，即将 (err, value) => ... 回调作为最后一个参数。 在回调中，第一个参数将是拒绝原因（如果 Promise 已解决，则为 null），第二个参数将是已解决的值。 |
| function promiseWrapper(original: (err: Object, value: Object) => void): Object | 参数为采用遵循常见的错误优先的回调风格的函数（也就是将 (err, value) => ... 回调作为最后一个参数），并返回一个返回 promise 的版本。 |
| isAnyArrayBuffer(value: Object): boolean | 检查输入的value是否是ArrayBuffer或SharedArrayBuffer类型。 |
| isArrayBufferView(value: Object): boolean | 检查输入的value是否是napi_int8_array或napi_uint8_array或napi_uint8_clamped_array或napi_int16_array或napi_uint16_array或napi_int32_array或napi_uint32_array或napi_float32_array或napi_float64_array数组或DataView类型。 |
| isArgumentsObject(value: Object): boolean | 检查输入的value是否是一个arguments对象类型。 |
| isArrayBuffer(value: Object): boolean | 检查输入的value是否是ArrayBuffer类型。 |
| isAsyncFunction(value: Object): boolean | 检查输入的value是否是异步函数类型。 |
| isBigInt64Array(value: Object): boolean | 检查输入的value是否是BigInt64Array数组类型。 |
| isBigUint64Array(value: Object): boolean | 检查输入的value是否是BigUint64Array数组类型。 |
| isBooleanObject(value: Object): boolean | 检查输入的value是否是一个布尔对象类型。 |
| isBoxedPrimitive(value: Object): boolean | 检查输入的value是否是Boolean或Number或String或Symbol对象类型。 |
| isDataView(value: Object): boolean | 检查输入的value是否是DataView类型。 |
| isDate(value: Object): boolean | 检查输入的value是否是Date类型。 |
| isExternal(value: Object): boolean | 检查输入的value是否是一个native External值类型。 |
| isFloat32Array(value: Object): boolean | 检查输入的value是否是Float32Array数组类型。 |
| isFloat64Array(value: Object): boolean | 检查输入的value是否是Float64Array数组类型。 |
| isGeneratorFunction(value: Object): boolean | 检查输入的value是否是一个generator函数类型。 |
| isGeneratorObject(value: Object): boolean | 检查输入的value是否是一个generator对象类型。 |
| isInt8Array(value: Object): boolean | 检查输入的value是否是Int8Array数组类型。 |
| isInt16Array(value: Object): boolean | 检查输入的value是否是Int16Array数组类型。 |
| isInt32Array(value: Object): boolean | 检查输入的value是否是Int32Array数组类型。 |
| isMap(value: Object): boolean | 检查输入的value是否是Map类型。 |
| isMapIterator(value: Object): boolean | 检查输入的value是否是Map的iterator类型。 |
| isModuleNamespaceObject(value: Object): boolean | 检查输入的value是否是Module Namespace Object对象类型。 |
| isNativeError(value: Object): boolean | 检查输入的value是否是Error类型。 |
| isNumberObject(value: Object): boolean | 检查输入的value是否是Number对象类型。 |
| isPromise(value: Object): boolean | 检查输入的value是否是Promise类型。 |
| isProxy(value: Object): boolean | 检查输入的value是否是Proxy类型。 |
| isRegExp(value: Object): boolean | 检查输入的value是否是RegExp类型。 |
| isSet(value: Object): boolean | 检查输入的value是否是Set类型。 |
| isSetIterator(value: Object): boolean | 检查输入的value是否是Set的iterator类型。 |
| isSharedArrayBuffer(value: Object): boolean | 检查输入的value是否是SharedArrayBuffer类型。 |
| isStringObject(value: Object): boolean | 检查输入的value是否是一个String对象类型。 |
| isSymbolObject(value: Object): boolean | 检查输入的value是否是一个Symbol对象类型。 |
| isTypedArray(value: Object): boolean | 检查输入的value是否是TypedArray包含的类型。 |
| isUint8Array(value: Object): boolean | 检查输入的value是否是Uint8Array数组类型。 |
| isUint8ClampedArray(value: Object): boolean | 检查输入的value是否是Uint8ClampedArray数组类型。 |
| isUint16Array(value: Object): boolean | 检查输入的value是否是Uint16Array数组类型。 |
| isUint32Array(value: Object): boolean | 检查输入的value是否是Uint32Array数组类型。 |
| isWeakMap(value: Object): boolean | 检查输入的value是否是WeakMap类型。 |
| isWeakSet(value: Object): boolean | 检查输入的value是否是WeakSet类型。 |
| add(element: T): boolean | 在ArrayList尾部插入元素。 |
| insert(element: T, index: number): void | 在长度范围内任意位置插入指定元素。 |
| has(element: T): boolean | 判断此ArrayList中是否含有该指定元素。 |
| getIndexOf(element: T): number | 返回指定元素第一次出现时的下标值，查找失败返回-1。 |
| removeByIndex(index: number): T | 根据元素的下标值查找元素，返回元素后将其删除。 |
| remove(element: T): boolean | 删除查找到的第一个指定的元素。 |
| getLastIndexOf(element: T): number | 返回指定元素最后一次出现时的下标值，查找失败返回-1。 |
| removeByRange(fromIndex: number, toIndex: number): void | 从一段范围内删除元素，包括起始值但不包括终止值。 |
| replaceAllElements(callbackFn: (value: T, index?: number, arrlist?: ArrayList<T>) => T,
thisArg?: Object): void | 用户操作ArrayList中的元素，用操作后的元素替换原元素并返回操作后的元素。 |
| forEach(callbackFn: (value: T, index?: number, arrlist?: ArrayList<T>) => void,
  thisArg?: Object): void | 通过回调函数来遍历ArrayList实例对象上的元素以及元素对应的下标。 |
| sort(comparator?: (firstValue: T, secondValue: T) => number): void | 对ArrayList中的元素排序。 |
| subArrayList(fromIndex: number, toIndex: number): ArrayList<T> | 根据下标截取ArrayList中的一段元素，并返回这一段ArrayList实例，包括起始值但不包括终止值。 |
| clear(): void | 清除ArrayList中的所有元素，并把length置为0。 |
| clone(): ArrayList<T> | 克隆一个与ArrayList相同的实例，并返回克隆后的实例。修改克隆后的实例并不会影响原实例。 |
| getCapacity(): number | 获取当前实例的容量大小。 |
| convertToArray(): Array<T> | 把当前ArrayList实例转换成数组，并返回转换后的数组。 |
| isEmpty(): boolean | 判断该ArrayList是否为空。 |
| increaseCapacityTo(newCapacity: number): void | 如果传入的新容量大于或等于ArrayList中的元素个数，将容量变更为新容量。 |
| trimToCurrentLength(): void | 把容量限制为当前的length大小。 |
| insertFront(element: T): void | 在deque头部插入元素。 |
| insertEnd(element: T): void | 在deque尾部插入元素。 |
| has(element: T): boolean | 判断此Deque中是否含有该指定元素。 |
| getFirst(): T | 获取Deque实例中的头元素。 |
| getLast(): T | 获取Deque实例中的尾元素。 |
| popFirst(): T | 删除并返回双端队列的首元素。 |
| popLast(): T | 删除并返回双端队列的尾元素。 |
| forEach(callbackFn: (value: T, index?: number, deque?: Deque<T>) => void,thisArg?: Object): void |
通过回调函数来遍历Deque实例对象上的元素以及元素对应的下标。 |
| isEmpty(): boolean | 判断该HashMap是否为空。 |
| hasKey(key: K): boolean | 判断此HashMap中是否含有该指定key。 |
| hasValue(value: V): boolean | 判断此HashMap中是否含有该指定value。 |
| get(key: K): V | 获取指定key所对应的value。 |
| setAll(map: HashMap<K, V>): void | 将一个HashMap中的所有元素组添加到另一个hashMap中。 |
| set(key: K, value: V): Object | 向HashMap中添加一组数据。 |
| remove(key: K): V | 删除指定key所对应元素。 |
| clear(): void | 清除HashMap中的所有元素,并把length置为0。 |
| keys(): IterableIterator<K> | 返回包含此映射中包含的键名的新迭代器对象。 |
| values(): IterableIterator<V> | 返回包含此映射中包含的键值的新迭代器对象。 |
| replace(key: K, newValue: V): boolean | 对HashMap中一组数据进行更新（替换）。 |
| forEach(callbackFn: (value?: V, key?: K, map?: HashMap<K, V>) => void,thisArg?: Object): void |
通过回调函数来遍历HashMap实例对象上的元素以及元素对应的下标。 |
| entries(): IterableIterator<[K, V]> | 返回包含此映射中包含的键值对的新迭代器对象。 |
| isEmpty(): boolean | 判断该HashSet是否为空。 |
| has(value: T): boolean | 判断此HashSet中是否含有该指定元素。 |
| add(value: T): boolean | 向HashSet中添加数据。 |
| remove(value: T): boolean | 删除指定的元素。 |
| clear(): void | 清除HashSet中的所有元素,并把length置为0。 |
| forEach(callbackFn: (value?: T, key?: T, set?: HashSet<T>) => void,thisArg?: Object): void |
通过回调函数来遍历实例对象上的元素以及元素对应的下标。 |
| values(): IterableIterator<T> | 返回包含此映射中包含的键值的新迭代器对象。 |
| entries(): IterableIterator<[T, T]> | 返回包含此映射中包含的键值对的新迭代器对象。 |
| hasAll(map: LightWeightMap<K, V>): boolean | 判断此LightWeightMap中是否含有该指定map中的所有元素。 |
| hasKey(key: K): boolean | 判断此LightWeightMap中是否含有该指定key。 |
| hasValue(value: V): boolean | 判断此LightWeightMap中是否含有该指定value。 |
| increaseCapacityTo(minimumCapacity: number): void | 将当前LightWeightMap扩容至可以容纳指定数量元素。 |
| entries(): IterableIterator<[K, V]> | 返回包含此映射中包含的键值对的新迭代器对象。 |
| get(key: K): V | 获取指定key所对应的value。 |
| getIndexOfKey(key: K): number | 查找key元素第一次出现的下标值，如果没有找到该元素返回-1。 |
| getIndexOfValue(value: V): number | 查找value元素第一次出现的下标值，如果没有找到该元素返回-1。 |
| isEmpty(): boolean | 判断该LightWeightMap是否为空。 |
| getKeyAt(index: number): K | 查找指定下标的元素键值对中key值，否则返回undefined。 |
| keys(): IterableIterator<K> | 返回包含此映射中包含的键的新迭代器对象。 |
| setAll(map: LightWeightMap<K, V>): void | 将一个LightWeightMap中的所有元素组添加到另一个lightWeightMap中。 |
| set(key: K, value: V): Object | 向LightWeightMap中添加一组数据。 |
| remove(key: K): V | 删除并返回指定key映射的元素。 |
| removeAt(index: number): boolean | 删除指定下标对应的元素。 |
| clear(): void | 清除LightWeightMap中的所有元素,并把length置为0。 |
| setValueAt(index: number, newValue: V): boolean | 替换指定下标对应键值对中的元素。 |
| forEach(callbackFn: (value?: V, key?: K, map?: LightWeightMap<K, V>) => void,thisArg?: Object): void |
通过回调函数来遍历实例对象上的元素以及元素对应的下标。 |
| [Symbol.iterator](): IterableIterator<[K, V]> | 返回一个迭代器，迭代器的每一项都是一个 JavaScript 对象,并返回该对象。 |
| toString(): String | 将此映射中包含的键值对拼接成字符串，并返回字符串类型。 |
| getValueAt(index: number): V | 获取指定下标对应键值对中的元素。 |
| values(): IterableIterator<V> | 返回包含此映射中包含的键值的新迭代器对象。 |
| add(obj: T): boolean | 向此容器中添加数据。 |
| addAll(set: LightWeightSet<T>): boolean | 将另一个容器中的所有元素组添加到当前容器中。 |
| hasAll(set: LightWeightSet<T>): boolean | 判断此容器中是否含有该指定set中的所有元素。 |
| has(key: T): boolean | 判断此容器中是否含有该指定key。 |
| equal(obj: Object): boolean | 判断此容器中是否含有该指定obj同类型的对象。 |
| increaseCapacityTo(minimumCapacity: number): void | 将当前容器扩容至可以容纳指定数量元素。 |
| getIndexOf(key: T): number | 获取指定key所对应的下标。 |
| remove(key: T): T | 删除并返回指定key对应的元素。 |
| removeAt(index: number): boolean | 删除指定下标所对应的元素。 |
| clear(): void | 清除容器中的所有元素，并把length置为0。 |
| forEach(callbackFn: (value?: T, key?: T, set?: LightWeightSet<T>) => void,thisArg?: Object): void |
通过回调函数来遍历LightWeightSet实例对象上的元素以及元素对应的下标。 |
| [Symbol.iterator](): IterableIterator<T> | 返回一个迭代器，迭代器的每一项都是一个 JavaScript 对象，并返回该对象。 |
| toString(): String | 获取包含容器中所有键和值的字符串。 |
| toArray(): Array<T> | 获取包含此容器中所有对象的数组。 |
| getValueAt(index: number): T | 获取此容器中指定下标对应的元素。 |
| values(): IterableIterator<T> | 返回包含此映射中包含的键值的新迭代器对象。 |
| entries(): IterableIterator<[T, T]> | 返回包含此映射中包含的键值对的新迭代器对象。 |
| isEmpty(): boolean | 判断该容器是否为空。 |
| add(element: T): boolean | 在LinkedList尾部插入元素。 |
| insert(index: number, element: T): void | 在长度范围内任意插入指定元素。 |
| get(index: number): T | 根据下标获取LinkedList中的元素。 |
| addFirst(element: T): void | 在LinkedList头部插入元素。 |
| removeFirst(): T | 删除并返回LinkedList的第一个元素。 |
| removeLast(): T | 删除并返回LinkedList的最后一个元素。 |
| has(element: T): boolean | 判断此LinkedList中是否含有该指定元素。 |
| getIndexOf(element: T): number | 返回指定元素第一次出现时的下标值，查找失败返回-1。 |
| removeByIndex(index: number): T | 根据元素的下标值查找元素，返回元素后将其删除。 |
| remove(element: T): boolean | 删除查找到的第一个指定的元素。 |
| removeFirstFound(element: T): boolean | 删除第一次出现的指定元素。 |
| removeLastFound(element: T): boolean | 删除最后一次出现的指定元素。 |
| getLastIndexOf(element: T): number | 返回指定元素最后一次出现时的下标值，查找失败返回-1。 |
| getFirst(): T | 获取LinkedList实例中的第一个元素。 |
| getLast(): T | 获取LinkedList实例中的最后一个元素。 |
| set(index: number, element: T): T | 将此LinkedList中指定位置的元素替换为指定元素。 |
| forEach(callbackFn: (value: T, index?: number, LinkedList?: LinkedList<T>) => void,thisArg?: Object): void |
通过回调函数来遍历LinkedList实例对象上的元素以及元素对应的下标。 |
| clear(): void | 清除LinkedList中的所有元素，并把length置为0。 |
| clone(): LinkedList<T> | 克隆一个与LinkedList相同的实例，并返回克隆后的实例。修改克隆后的实例并不会影响原实例。 |
| convertToArray(): Array<T> | 把当前LinkedList实例转换成数组，并返回转换后的数组。 |
| [Symbol.iterator](): IterableIterator<T> | 返回一个迭代器，迭代器的每一项都是一个 JavaScript 对象，并返回该对象。 |
| add(element: T): boolean | 在List尾部插入元素。 |
| insert(element: T, index: number): void | 在长度范围内任意位置插入指定元素。 |
| get(index: number): T | 根据下标获取List中的元素。 |
| has(element: T): boolean | 判断此List中是否含有该指定元素。 |
| getIndexOf(element: T): number | 查找指定元素第一次出现的下标值，查找失败返回-1。 |
| removeByIndex(index: number): T | 根据元素的下标值查找元素，返回元素后将其删除。 |
| remove(element: T): boolean | 删除查找到的第一个指定的元素。 |
| getLastIndexOf(element: T): number | 查找指定元素最后一次出现的下标值，查找失败返回-1。 |
| getFirst(): T | 获取List实例中的第一个元素。 |
| getLast(): T | 获取List实例中的最后一个元素。 |
| set(index: number, element: T): T | 将此 List 中指定位置的元素替换为指定元素。 |
| equal(obj: Object): boolean | 比较指定对象与此List是否相等。 |
| forEach(callbackFn: (value: T, index?: number, List?: List<T>) => void,thisArg?: Object): void |
通过回调函数来遍历List实例对象上的元素以及元素对应的下标。 |
| sort(comparator: (firstValue: T, secondValue: T) => number): void | 对List中的元素进行一个排序操作。 |
| clear(): void | 清除List中的所有元素，并把length置为0。 |
| getSubList(fromIndex: number, toIndex: number): List<T> |
根据下标截取List中的一段元素，并返回这一段List实例，包括起始值但不包括终止值。 |
| replaceAllElements(callbackFn: (value: T, index?: number, list?: List<T>) => T,thisArg?: Object): void;T |
用户操作List中的元素,用操作后的元素替换原元素并返回操作后的元素。 |
| convertToArray(): Array<T> | 把当前List实例转换成数组，并返回转换后的数组。 |
| isEmpty(): boolean | 判断该List是否为空。 |
| [Symbol.iterator](): IterableIterator<T> | 返回一个迭代器，迭代器的每一项都是一个 JavaScript 对象，并返回该对象。 |
| add(key: number, value: T): void | 向容器中添加一组数据。 |
| clear(): void | 清除容器中的所有元素，并把length置为0。 |
| clone(): PlainArray<T> | 克隆一个实例，并返回克隆后的实例。修改克隆后的实例并不会影响原实例。 |
| has(key: number): boolean | 判断此容器中是否含有该指定key。 |
| get(key: number): T | 获取指定key所对应的value。 |
| getIndexOfKey(key: number): number | 查找指定key第一次出现的下标值，如果没有找到该key返回-1。 |
| getIndexOfValue(value: T): number | 查找指定value元素第一次出现的下标值，如果没有找到该value元素返回-1。 |
| isEmpty(): boolean | 判断该容器是否为空。 |
| getKeyAt(index: number): number | 查找指定下标元素键值对中的key值。 |
| remove(key: number): T | 删除指定key对应元素。 |
| removeAt(index: number): T | 删除指定下标对应的元素。 |
| removeRangeFrom(index: number, size: number): number | 删除一定范围内的元素。 |
| setValueAt(index: number, value: T): void | 替换容器中指定下标对应键值对中的键值。 |
| toString(): String | 获取包含容器中所有键和值的字符串。 |
| getValueAt(index: number): T | 查找指定下标元素键值对中的Value值，失败返回undefined。 |
| forEach(callbackFn: (value: T, index?: number, PlainArray?: PlainArray<T>) => void,thisArg?: Object): void |
通过回调函数来遍历实例对象上的元素以及元素对应的下标。 |
| [Symbol.iterator](): IterableIterator<[number, T]> | 返回一个包含key-value键值对的迭代器对象，其中key是number类型。 |
| add(element: T): boolean | 在队列尾部插入元素。 |
| getFirst(): T | 获取队列的头元素。 |
| pop(): T | 删除头元素并返回该删除元素。 |
| forEach(callbackFn: (value: T, index?: number, Queue?: Queue<T>) => void, thisArg?: Object): void; |
通过回调函数来遍历Queue实例对象上的元素以及元素对应的下标。 |
| [Symbol.iterator](): IterableIterator<T> | 返回一个迭代器，迭代器的每一项都是一个 JavaScript 对象,并返回该对象。 |
| isEmpty(): boolean | 判断该栈是否为空。 |
| peek(): T | 获取并返回栈顶元素。 |
| pop(): T | 删除栈顶元素并返回该删除元素。 |
| push(item: T): T | 在栈顶插入元素，并返回该元素。 |
| locate(element: T): number | 返回指定元素第一次出现时的下标值，查找失败返回-1。 |
| forEach(callbackFn: (value: T, index?: number, stack?: Stack<T>) => void,thisArg?: Object): void |
通过回调函数来遍历Stack实例对象上的元素以及元素对应的下标。 |
| [Symbol.iterator](): IterableIterator<T> | 返回一个迭代器，迭代器的每一项都是一个 JavaScript 对象,并返回该对象。 |
| isEmpty(): boolean | 判断该容器是否为空。 |
| hasKey(key: K): boolean | 判断此容器中是否含有该指定key。 |
| hasValue(value: V): boolean | 判断此容器中是否含有该指定value。 |
| get(key: K): V | 获取指定key所对应的value。 |
| getFirstKey(): K | 获取容器中排序第一的key。 |
| getLastKey(): K | 获取容器中排序最后的key。 |
| setAll(map: TreeMap<K, V>): void | 将一个TreeMap中的所有元素组添加到另一个TreeMap中。 |
| set(key: K, value: V): Object | 向容器中添加一组数据。 |
| remove(key: K): V | 删除指定key对应的元素。 |
| clear(): void | 清除容器中的所有元素，并把length置为0。 |
| getLowerKey(key: K): K | 获取容器中比传入key排序靠前一位的key。 |
| getHigherKey(key: K): K | 获取容器中比传入key排序靠后一位的key。 |
| keys(): IterableIterator<K> | 返回包含此映射中包含的键的新迭代器对象。 |
| values(): IterableIterator<V> | 返回包含此映射中键值对的新迭代器对象。 |
| replace(key: K, newValue: V): boolean | 对容器中一组数据进行更新（替换）。 |
| forEach(callbackFn: (value?: V, key?: K, map?: TreeMap<K, V>) => void, thisArg?: Object): void; |
通过回调函数来遍历实例对象上的元素以及元素对应的下标。 |
| entries(): IterableIterator<[K, V]> | 返回包含此映射中键值对的新迭代器对象。 |
| [Symbol.iterator](): IterableIterator<[K, V]> | 返回一个迭代器，迭代器的每一项都是一个JavaScript对象，并返回该对象。 |
| isEmpty(): boolean | 判断该容器是否为空。 |
| has(value: T): boolean | 判断此容器中是否含有该指定元素。 |
| add(value: T): boolean | 向容器中添加一组数据。 |
| remove(value: T): boolean | 删除指定的元素。 |
| clear(): void | 清除容器中的所有元素，并把length置为0。 |
| getFirstValue(): T | 获取容器中排序第一的数据。 |
| getLastValue(): T | 获取容器中排序最后的数据。 |
| getLowerValue(key: T): T | 获取容器中比传入元素排序靠前一位的元素。 |
| getHigherValue(key: T): T | 获取容器中比传入元素排序靠后一位的元素。 |
| popFirst(): T | 删除容器中排序最前的数据。 |
| popLast(): T | 删除容器中排序最后的数据。 |
| forEach(callbackFn: (value?: T, key?: T, set?: TreeSet<T>) => void, thisArg?: Object): void; |
通过回调函数来遍历实例对象上的元素以及元素对应的下标。 |
| values(): IterableIterator<T> | 返回包含此映射中键值对的新迭代器对象。 |
| entries(): IterableIterator<[T, T]> | 返回包含此映射中键值对的新迭代器对象。 |
| [Symbol.iterator](): IterableIterator<T> | 返回一个迭代器，迭代器的每一项都是一个JavaScript对象，并返回该对象。 |

printf中每个说明符都替换为来自相应参数的转换后的值。 支持的说明符有:
| 式样化字符 | 式样要求 |
| -------- | -------- |
|    %s:  | String 将用于转换除 BigInt、Object 和 -0 之外的所有值。|
|    %d:  | Number 将用于转换除 BigInt 和 Symbol 之外的所有值。|
|    %i:  | parseInt(value, 10) 用于除 BigInt 和 Symbol 之外的所有值。|
|    %f:  | parseFloat(value) 用于除 Symbol 之外的所有值。|
|    %j:  | JSON。 如果参数包含循环引用，则替换为字符串 '[Circular]'。|
|    %o:  | Object. 具有通用 JavaScript 对象格式的对象的字符串表示形式。类似于具有选项 { showHidden: true, showProxy: true } 的 util.inspect()。这将显示完整的对象，包括不可枚举的属性和代理。|
|    %O:  | Object. 具有通用 JavaScript 对象格式的对象的字符串表示形式。类似于没有选项的 util.inspect()。 这将显示完整的对象，但不包括不可枚举的属性和代理。|
|    %c:  | 此说明符被忽略，将跳过任何传入的 CSS 。|
|    %%:  | 单个百分号 ('%')。 这不消耗待式样化参数。|

#### 2.3.2. 使用说明
各接口使用方法如下：

1.readonly encoding()

```
import util from '@ohos.util'
var textEncoder = new util.TextEncoder();
var getEncoding = textEncoder.encoding();
```
2.encode()
```
import util from '@ohos.util'
var textEncoder = new util.TextEncoder();
var result = textEncoder.encode('abc');
```
3.encodeInto()
```
import util from '@ohos.util'
var textEncoder = new util.TextEncoder();
var obj = textEncoder.encodeInto('abc', dest);
```
4.textDecoder()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
```
5.readonly encoding()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var getEncoding = textDecoder.encoding();
```
6.readonly fatal()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var fatalStr = textDecoder.fatal();
```
7.readonly ignoreBOM()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var ignoreBom = textDecoder.ignoreBOM();
```
8.decode()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var result = textDecoder.decode(input, {stream : true});
```
9.decodeWithStream()
```
import util from '@ohos.util'
var textDecoder = new util.textDecoder("utf-16be", {fatal : true, ignoreBOM : false});
var result = textDecoder.decodeWithStream(input, {stream : true});
```
10.printf()
```
import util from '@ohos.util'
var format = "%%%o%%%i%s";
var value =  function aa(){};
var value1 = 1.5;
var value2 = "qwer";
var result = util.printf(format,value,value1,value2);
```
11.getErrorString()
```
import util from '@ohos.util'
var errnum = 13;
var result = util.getErrorString(errnum);
```
12.callbackWrapper()
```
import util from '@ohos.util'
async function promiseFn() {
    return Promise.resolve('value');
};
var cb = util.callbackWrapper(promiseFn);
cb((err, ret) => {
    expect(err).strictEqual(null);
    expect(ret).strictEqual('value');
})
```
13.promiseWrapper()
```
import util from '@ohos.util'
function aysnFun(str1, str2, callback) {
    if (typeof str1 === 'string' && typeof str1 === 'string') {
        callback(null, str1 + str2);
    } else {
        callback('type err');
    }
}
let newPromiseObj = util.promiseWrapper(aysnFun)("Hello", 'World');
newPromiseObj.then(res => {
    expect(res).strictEqual('HelloWorld');
})
```
14.encodeSync()
```
import util from '@ohos.util'
var that = new util.Base64();
var array = new Uint8Array([115,49,51]);
var result = that.encodeSync(array);
```
15.encodeToStringSync()
```
import util from '@ohos.util'
var that = new util.Base64();
var array = new Uint8Array([115,49,51]);
var result = that.encodeToStringSync(array);
```
16.decodeSync()
```
import util from '@ohos.util'
var that = new util.Base64()
var buff = 'czEz';
var result = that.decodeSync(buff);

```
17.encode()
```
import util from '@ohos.util'
var that = new util.Base64()
var array = new Uint8Array([115,49,51]);
await that.encode(array).then(val=>{
})
done()
```
18.encodeToString()
```
import util from '@ohos.util'
var that = new util.Base64()
var array = new Uint8Array([115,49,51]);
await that.encodeToString(array).then(val=>{
})
done()
```
19.decode()
```
import util from '@ohos.util'
var that = new util.Base64()
var buff = 'czEz';
await that.decode(buff).then(val=>{
})
done()
```
20.createRationalFromString()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(0, 0);
var res = pro.createRationalFromString("-1:2");
var result1 = res.valueOf();
```
21.compareTo()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var proc = new util.RationalNumber(3, 4);
var res = pro.compareTo(proc);
```
22.equals()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var proc = new util.RationalNumber(3, 4);
var res = pro.equals(proc);
```
23.valueOf()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var res = pro.valueOf();
```
24.getCommonDivisor()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(0, 0);
var res = pro.getCommonDivisor(4, 8);
```
25.getDenominator()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(2, 1);
var res = pro.getDenominator();
```
26.getNumerator()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.getNumerator();
```
27.isFinite()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.isFinite();
```
28.isNaN()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.isNaN();
```
29.isZero()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.isZero();
```
30.toString()
```
import util from '@ohos.util'
var pro = new util.RationalNumber(-2, 1);
var res = pro.toString();
```
31.updateCapacity()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.updateCapacity(100);
```
32.toString()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.get(2);
pro.remove(20);
var result = pro.toString();
```
33.values()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.put(2,"anhu");
pro.put("afaf","grfb");
var result = pro.values();
```
34.length
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.put(1,8);
var result = pro.length;
```
35.getCapacity()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.getCapacity();
```
36.clear()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.clear();
```
37.getCreateCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(1,8);
var result = pro.getCreateCount();
```
38.getMissCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.get(2)
var result = pro.getMissCount();
```
39.getRemovalCount()
```

import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.updateCapacity(2);
pro.put(50,22);
var result = pro.getRemovalCount();

```
40.getMatchCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
pro.get(2);
var result = pro.getMatchCount();
```
41.getPutCount()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.getPutCount();
```
42.isEmpty()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.isEmpty();
```
43.get()

```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.get(2);
```
44.put()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.put(2,10);
```
45.keys()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.keys();
```
46.remove()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.remove(20);
```
47.contains()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.contains(20);
```
48.createDefault()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
var result = pro.createDefault(50);
```
49.entries()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro.put(2,10);
var result = pro.entries();
```
50.\[Symbol.iterator\]()
```
import util from '@ohos.util'
var pro = new util.LruBuffer();
pro .put(2,10);
var result = pro[symbol.iterator]();
```
51.afterRemoval()
```
import util from '@ohos.util'
var arr = [ ];
class ChildLruBuffer extends util.LruBuffer
{
    constructor()
    {
        super();
    }
    static getInstance()
    {
        if(this.instance ==  null)
        {
            this.instance = new ChildLruBuffer();
        }
        return this.instance;
    }
    afterRemoval(isEvict, key, value, newValue)
    {
        if (isEvict === false)
        {
            arr = [key, value, newValue];
        }
    }
}
ChildLruBuffer.getInstance().afterRemoval(false,10,30,null)
```
Scope接口中构造新类，实现compareTo方法。

```
class Temperature {
    constructor(value) {
        this._temp = value;
    }
    compareTo(value) {
        return this._temp >= value.getTemp();
    }
    getTemp() {
        return this._temp;
    }
    toString() {
        return this._temp.toString();
    }
}
```

52.constructor()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
```

53.toString()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var result = range.toString() // => [30,40]
```

54.intersect()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var rangeFir = new Scope(tempMiDF, tempMidS);
var result = range.intersect(rangeFir)  // => [35,39]
```

55.intersect()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var range = new Scope(tempLower, tempUpper);
var result = range.intersect(tempMiDF, tempMidS)  // => [35,39]
```

56.getUpper()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var result = range.getUpper() // => 40
```

57.getLower()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var result = range.getLower() // => 30
```

58.expand()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var range = new Scope(tempLower, tempUpper);
var result = range.expand(tempMiDF, tempMidS)  // => [30,40]
```

59.expand()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var tempMidS = new Temperature(39);
var range = new Scope(tempLower, tempUpper);
var rangeFir = new Scope(tempMiDF, tempMidS);
var result = range.expand(rangeFir) // => [30,40]
```

60.expand()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var range = new Scope(tempLower, tempUpper);
var result = range.expand(tempMiDF)  // => [30,40]
```

61.contains()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var range = new Scope(tempLower, tempUpper);
var result = range.contains(tempMiDF) // => true
```

62.contains()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var range = new Scope(tempLower, tempUpper);
var tempLess = new Temperature(20);
var tempMore = new Temperature(45);
var rangeSec = new Scope(tempLess, tempMore);
var result = range.contains(rangeSec) // => true
```

63.clamp()

```
var tempLower = new Temperature(30);
var tempUpper = new Temperature(40);
var tempMiDF = new Temperature(35);
var range = new Scope(tempLower, tempUpper);
var result = range.clamp(tempMiDF) // => 35
```
64.isAnyArrayBuffer()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isAnyArrayBuffer(new ArrayBuffer([]))
```
65.isArrayBufferView()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isArrayBufferView(new DataView(new ArrayBuffer(16)));
```
66.isArgumentsObject()
```
import util from '@ohos.util'
function foo() {
        var result = proc.isArgumentsObject(arguments);
    }
var f = foo();
```
67.isArrayBuffer()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isArrayBuffer(new ArrayBuffer([]));
```
68.isAsyncFunction()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isAsyncFunction(async function foo() {});
```
69.isBigInt64Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBigInt64Array(new Int16Array([]));
```
70.isBigUint64Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBigUint64Array(new Int16Array([]));
```
71.isBooleanObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBooleanObject(new Boolean(false));
```
72.isBoxedPrimitive()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isBoxedPrimitive(new Boolean(false));
```
73.isDataView()
```
import util from '@ohos.util'
var proc = new util.Types();
const ab = new ArrayBuffer(20);
var result = proc.isDataView(new DataView(ab));
```
74.isDate()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isDate(new Date());
```
75.isExternal()
```
import util from '@ohos.util'
const data = util.createExternalType();
var reult13 = proc.isExternal(data);
```
76.isFloat32Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isFloat32Array(new Float32Array([]));
```
77.isFloat64Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isFloat64Array(new Float64Array([]));
```
78.isGeneratorFunction()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isGeneratorFunction(function* foo() {});
```
79.isGeneratorObject()
```
import util from '@ohos.util'
var proc = new util.Types();
function* foo() {}
const generator = foo();
var result = proc.isGeneratorObject(generator);
```
80.isInt8Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isInt8Array(new Int8Array([]));
```
81.isInt16Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isInt16Array(new Int16Array([]));
```
82.isInt32Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isInt32Array(new Int32Array([]));
```
83.isMap()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isMap(new Map());
```
84.isMapIterator()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isMapIterator(map.keys());
```
85.isModuleNamespaceObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isModuleNamespaceObject(util);
```
86.isNativeError()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isNativeError(new TypeError());
```
87.isNumberObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isNumberObject(new Number(0));
```
88.isPromise()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isPromise(Promise.resolve(42));
```
89.isProxy()
```
import util from '@ohos.util'
var proc = new util.Types();
const target = {};
const proxy = new Proxy(target, {});
var result = proc.isProxy(proxy);
```
90.isRegExp()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isRegExp(new RegExp('abc'));
```
91.isSet()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isSet(new Set());
```
92.isSetIterator()
```
import util from '@ohos.util'
var proc = new util.Types();
const set = new Set();
var result = proc.isSetIterator(set.keys());
```
93.isSharedArrayBuffer()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isSharedArrayBuffer(new ArrayBuffer([]));
```
94.isStringObject()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isStringObject(new String('foo'));
```
95.isSymbolObject()
```
import util from '@ohos.util'
var proc = new util.Types();
const symbols = Symbol('foo');
var result = proc.isSymbolObject(Object(symbols));
```
96.isTypedArray()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isTypedArray(new Float64Array([]));
```
97.isUint8Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint8Array(new Uint8Array([]));
```
98.isUint8ClampedArray()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint8ClampedArray(new Uint8ClampedArray([]));
```
99.isUint16Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint16Array(new Uint16Array([]));
```
100.isUint32Array()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isUint32Array(new Uint32Array([]));
```
101.isWeakMap()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isWeakMap(new WeakMap());
```
102.isWeakSet()
```
import util from '@ohos.util'
var proc = new util.Types();
var result = proc.isWeakSet(new WeakSet());
```
103.add()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
let result = arrayList.add(8);
```
104.insert()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add("四");
arrayList.add("三");
arrayList.add(1);
arrayList.add("a");
arrayList.insert(8, 2);
```
105.add()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add("四");
arrayList.add("三");
arrayList.add(1);
arrayList.add("a");
arrayList.insert(8, 2);
let result = arrayList.has(8);
```
106.getIndexOf()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(1);
arrayList.add("三");
arrayList.add(1);
arrayList.add("a");
arrayList.insert(1, 2);
let result = arrayList.getIndexOf(1);
```
107.removeByIndex()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(1);
arrayList.add("三");
arrayList.add(1);
arrayList.add("a");
let result = arrayList.removeByIndex(2);
```
108.remove()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add("四");
arrayList.add("三");
arrayList.add(1);
arrayList.add("a");
let result = arrayList.remove("三");
```
109.getLastIndexOf()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add("四");
arrayList.add("三");
arrayList.add(1);
arrayList.add("a");
arrayList.add(1);
arrayList.add("b");
let result = arrayList.getLastIndexOf(1);
```
110.removeByRange()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add("四");
arrayList.add("三");
arrayList.add("a");
arrayList.add("b");
arrayList.add("c");
arrayList.removeByRange(1, 3);
```
111.replaceAllElements()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
arrayList.replaceAllElements((item, index) => {
    return (item = 2 * item);
});
```
112.forEach()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
let arr = [];
arrayList.forEach((item, index) => {
    arr.push(item);
});
```
113.sort()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
arrayList.sort((a, b) => a - b);
```
114.subArrayList()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
let result = arrayList.subArrayList(0, 5);
```
115.clear()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
arrayList.clear();
```
116.clone()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
let res = arrayList.clone();
```
117.getCapacity()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
let result = arrayList.getCapacity();
```
118.convertToArray()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
let arr = arrayList.convertToArray();
```
119.isEmpty()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.clear();
let result = arrayList.isEmpty();
```
120.increaseCapacityTo()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
arrayList.increaseCapacityTo(-1);
```
121.trimToCurrentLength()
```
import ArrayList from "@ohos.util.ArrayList"
let arrayList = new ArrayList();
arrayList.add(4);
arrayList.add(3);
arrayList.add(1);
arrayList.add(2);
arrayList.add(14);
arrayList.trimToCurrentLength();
```
122.insertFront()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
deque.insertFront("一");
```
123.insertEnd()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
let a = ["a", "b", "c"];
deque.insertEnd(a);
```
124.has()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
deque.insertEnd(6);
let result = deque.has(6);
```
125.getFirst()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
deque.insertFront("$");
let result = deque.getFirst();
```
126.getLast()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
deque.insertFront("$");
let result = deque.getLast();
```
127.popFirst()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
deque.insertFront(6);
let result = deque.popFirst();
```
128.popLast()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
deque.insertFront(11);
let result = deque.popLast();
```
129.forEach()
```
import Deque from "@ohos.util.Deque"
let deque = new Deque();
deque.insertEnd(1);
deque.insertEnd(2);
deque.insertEnd(3);
let arr = [];
deque.forEach((item, index) => {
    arr.push(item);
});
```
130.isEmpty()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
let result = hashMap.isEmpty();
```
131.hasKey()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
let result = hashMap.hasKey(3);
```
132.hasValue()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
let result = hashMap.hasValue("C");
```
133.get()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
let result = hashMap.get(3);
```
134.setAll()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
let hashMap1 = new HashMap();
hashMap1.set(1, 1);
hashMap1.set(2, 2);
hashMap.setAll(hashMap1);
```
135.set()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
```
136.remove()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
let result = hashMap.remove(3);
```
137.clear()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
hashMap.clear();
```
138.keys()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
hashMap.set(4, "D");
hashMap.set(5, "E");
let result = hashMap.keys();
```
139.values()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
hashMap.set(4, "D");
hashMap.set(5, "E");
let result = hashMap.values();
```
140.replace()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
hashMap.set(4, "D");
hashMap.set(5, "E");
let result = hashMap.replace(2, "G");
```
141.forEach()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
hashMap.set(4, "D");
hashMap.set(5, "E");
let vals = [];
let keys = [];
hashMap.forEach((value, key) => {
    keys.push(key);
    vals.push(value);
});
```
142.entries()
```
import HashMap from "@ohos.util.HashMap"
let hashMap = new HashMap();
hashMap.set(1, "A");
hashMap.set(2, "B");
hashMap.set(3, "C");
hashMap.set(4, "D");
hashMap.set(5, "E");
let result = hashMap.entries();
```
143.isEmpty()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add(1);
hashSet.add(2);
let result = hashSet.isEmpty();
```
144.has()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add(1);
hashSet.add(2);
let result = hashSet.has(1);
```
145.add()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add(1);
hashSet.add(2);
```
146.remove()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add(1);
hashSet.add(2);
let hashSet = hashSet.remove(1);
```
147.clear()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add(1);
hashSet.add(2);
hashSet.clear();
```
148.forEach()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add(1);
hashSet.add(2);
hashSet.add(3);
hashSet.add(4);
hashSet.add(5);
let arr = [];
hashSet.forEach((value, index) => {
    arr.push(value);
});
```
149.values()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add("A");
hashSet.add("B");
hashSet.add("C");
hashSet.add("D");
hashSet.add("E");
let res = hashSet.values();
```
150.entries()
```
import HashSet from "@ohos.util.HashSet"
let hashSet = new HashSet();
hashSet.add(1);
hashSet.add(2);
hashSet.add(3);
let res = hashSet.entries();
```
151.hasAll()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set("a", "A");
lightWeightMap.set("b", "B");
lightWeightMap.set("c", "C");
lightWeightMap.set("d", "D");
lightWeightMap.set("e", "E");
let lightWeightMap1 = new LightWeightMap();
lightWeightMap1.set("a", "A");
lightWeightMap1.set("d", "D");
let res = lightWeightMap.hasAll(lightWeightMap1);
```
152.hasKey()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set("a", "A");
lightWeightMap.set("b", "B");
lightWeightMap.set("c", "C");
let res = lightWeightMap.hasKey("a");
```
153.hasValue()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set("a", "A");
lightWeightMap.set("b", "B");
lightWeightMap.set("c", "C");
let res = lightWeightMap.hasValue("A");
```
154.increaseCapacityTo()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set("a", "A");
lightWeightMap.set("b", "B");
lightWeightMap.set("c", "C");
lightWeightMap.increaseCapacityTo(3);
```
155.entries()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.entries();
```
156.get()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.get(1);
```
157.getIndexOfKey()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.getIndexOfKey(2);
```
158.getIndexOfValue()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
lightWeightMap.set(4, "D");
lightWeightMap.set(5, "E");
lightWeightMap.setValueAt(4, "F");
let res = lightWeightMap.getIndexOfValue("F");
```
159.isEmpty()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
let res = lightWeightMap.isEmpty();
```
160.getKeyAt()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.getKeyAt(1);
```
161.keys()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.keys();
```
161.setAll()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
lightWeightMap.set(4, "D");
lightWeightMap.set(5, "E");
let lightWeightMap1 = new LightWeightMap();
lightWeightMap1.set(6, "A");
lightWeightMap1.set(7, "B");
lightWeightMap.setAll(lightWeightMap1);
```
162.set()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
```
163.remove()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
let res = lightWeightMap.remove(2);
```
164.removeAt()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
let res = lightWeightMap.removeAt(1);
```
165.clear()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.clear();
```
166.setValueAt()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.setValueAt(0, "a");
```
167.forEach()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
lightWeightMap.set(4, "D");
lightWeightMap.set(5, "E");
let arr = [];
lightWeightMap.forEach((value, index) => {
    arr.push(value);
});
```
168.[Symbol.iterator]()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
lightWeightMap.set(4, "D");
lightWeightMap.set(5, "E");
let iters = lightWeightMap[Symbol.iterator]();
```
169.toString()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.toString();
```
170.getValueAt()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.getValueAt(1);
```
171.values()
```
import LightWeightMap from "@ohos.util.LightWeightMap"
let lightWeightMap = new LightWeightMap();
lightWeightMap.set(1, "A");
lightWeightMap.set(2, "B");
lightWeightMap.set(3, "C");
let res = lightWeightMap.values();
```
172.add()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
```
173.addAll()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
lightWeightSet.add(4);
lightWeightSet.add(5);
let lightWeightSet1 = new LightWeightSet();
lightWeightSet1.add(6);
lightWeightSet1.add(7);
let res1 = lightWeightSet.addAll(lightWeightSet1);
```
174.hasAll()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add("a");
lightWeightSet.add("b");
lightWeightSet.add("c");
lightWeightSet.add("e");
let lightWeightSet1 = new LightWeightSet();
lightWeightSet1.add("a");
lightWeightSet1.add("d");
let res = lightWeightSet.hasAll(lightWeightSet1);
```
175.has()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add("a");
lightWeightSet.add("b");
lightWeightSet.add("c");
let res = lightWeightSet.has("a");
```
176.equal()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let obj = [1,2,3];
let res = lightWeightSet.equal(obj);
```
177.increaseCapacityTo()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.increaseCapacityTo(20);
```
178.getIndexOf()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.getIndexOf(2);
```
179.remove()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.remove(1);
```
180.removeAt()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.removeAt(1);
```
181.clear()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
lightWeightSet.clear();
```
182.forEach()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
lightWeightSet.add(4);
lightWeightSet.add(5);
let arr = [];
lightWeightSet.forEach((value, index) => {
    arr.push(value);
});
```
183.[Symbol.iterator]()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet[Symbol.iterator]();
```
184.toString()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.toString();
```
185.toArray()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.toArray();
```
186.getValueAt()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.getValueAt(1);
```
187.values()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.values();
```
188.entries()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.entries();
```
189.isEmpty()
```
import LightWeightSet from "@ohos.util.LightWeightSet"
let lightWeightSet = new LightWeightSet();
lightWeightSet.add(1);
lightWeightSet.add(2);
lightWeightSet.add(3);
let res = lightWeightSet.isEmpty();
```
190.add()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("四");
```
191.insert()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
linkedList.add("a");
linkedList.add("b");
let res = linkedList.insert(3, "d");
```
192.get()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res1 = linkedList.get(2);
```
193.addFirst()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
linkedList.addFirst("e");
```
194.removeFirst()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.removeFirst();
```
195.removeLast()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.removeLast();
```
196.has()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.has(1);
```
197.getIndexOf()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.getIndexOf("b");
```
198.removeByIndex()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.removeByIndex(2);
```
199.remove()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.remove("a");
```
200.removeFirstFound()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.removeFirstFound("b");
```
201.removeLastFound()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.removeLastFound("b");
```
202.getLastIndexOf()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
linkedList.add("a");
linkedList.add("b");
linkedList.add("b");
let res = linkedList.getLastIndexOf("a");
```
203.getFirst()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
linkedList.add("a");
linkedList.add("b");
linkedList.add("b");
let res = linkedList.getFirst();
```
204.getLast()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
linkedList.add("a");
linkedList.add("b");
linkedList.add("b");
let res = linkedList.getLast();
```
205.set()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.set(2, "d");
```
206.forEach()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add(8);
linkedList.add("一");
linkedList.add("二");
linkedList.add(5);
let c = [1, 2, 3, 4];
linkedList.add(c);
linkedList.add(6);
linkedList.add("三");
linkedList.add("四");
let arr = [];
linkedList.forEach((item, index) => {
    arr.push(item);
});
```
207.clear()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let res = linkedList.clear();
```
208.clone()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
let linkedList1 = linkedList.clone();
```
209.convertToArray()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add(4);
linkedList.add(3);
linkedList.add(1);
linkedList.add(2);
linkedList.add(14);
let res = linkedList.convertToArray();
```
210.[Symbol.iterator]()
```
import LinkedList from "@ohos.util.LinkedList"
let linkedList = new LinkedList();
linkedList.add("a");
linkedList.add("b");
linkedList.add("c");
linkedList.addFirst("e");
let itr = linkedList[Symbol.iterator]();
```
211.add()
```
import List from "@ohos.util.List"
let list = new List();
list.add("四");
```
212.insert()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("a");
list.add("b");
let res = list.insert("d", 3);
```
213.get()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("a");
let res = list.set(2, "d");
let res1 = list.get(2);
```
214.has()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
let res = list.has(1);
```
215.getIndexOf()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("b");
let res = list.getIndexOf("b");
```
216.removeByIndex()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("b");
let res = list.removeByIndex(2);
```
217.remove()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("b");
let res = list.remove("a");
```
218.getLastIndexOf()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("b");
let res = list.getLastIndexOf("F");
```
219.getFirst()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("b");
let res = list.getFirst();
```
220.getLast()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("b");
let res = list.getLast();
```
221.set()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
list.add("a");
let res = list.set(2, "d");
```
222.equal()
```
import List from "@ohos.util.List"
let list = new List();
let list1 = new List();
let res = list.equal(list1);
```
223.forEach()
```
import List from "@ohos.util.List"
let list = new List();
let num = 0;
list.forEach((item, index) => {
    num++;
});
```
224.sort()
```
import List from "@ohos.util.List"
let list = new List();
list.add(4);
list.add(3);
list.add(1);
list.sort((a, b) => a - b);
```
225.clear()
```
import List from "@ohos.util.List"
let list = new List();
list.add(4);
list.add(3);
list.add(1);
list.clear();
```
226.getSubList()
```
import List from "@ohos.util.List"
let list = new List();
list.add(4);
list.add(3);
list.add(1);
list.add(2);
list.add(14);
let res = list.getSubList(2, 4);
```
227.replaceAllElements()
```
import List from "@ohos.util.List"
let list = new List();
let num = 0;
list.replaceAllElements((item, index) => {
    num++;
});
```
228.convertToArray()
```
import List from "@ohos.util.List"
let list = new List();
const res = list.convertToArray();
```
229.isEmpty()
```
import List from "@ohos.util.List"
let list = new List();
let res = list.isEmpty();
```
230.[Symbol.iterator]()
```
import List from "@ohos.util.List"
let list = new List();
list.add("a");
list.add("b");
list.add("c");
let itr = list[Symbol.iterator]();
```
231.add()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
```
232.clear()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
plainArray.clear();
```
233.clone()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let clonePlainarray = plainArray.clone();
```
234.has()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.has(6);
```
235.get()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let value = plainArray.get(2);
```
236.getIndexOfKey()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.getIndexOfKey(9);
```
237.getIndexOfValue()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.getIndexOfValue("Asad");
```
238.isEmpty()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.isEmpty();
```
239.getKeyAt()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.getKeyAt(2);
```
240.remove()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.remove(2);
```
241.removeAt()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.removeAt(2);
```
242.removeRangeFrom()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
plainArray.removeRangeFrom(2, 2);
```
243.setValueAt()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
plainArray.setValueAt(2, "V");
```
244.toString()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res1 = plainArray.toString();
```
245.getValueAt()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let res = plainArray.getValueAt(2);
```
246.forEach()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let arr = [];
res.forEach((value, index) => {
    arr.push(value);
});
```
247.[Symbol.iterator]()
```
import PlainArray from "@ohos.util.PlainArray"
let plainArray = new PlainArray();
plainArray.add(1, "A");
plainArray.add(2, "B");
plainArray.add(3, "C");
let iters = plainArray[Symbol.iterator]();
```
248.add()
```
import Queue from "@ohos.util.Queue"
let queue = new Queue();
queue.add("四");
```
249.getFirst()
```
import Queue from "@ohos.util.Queue"
let queue = new Queue();
queue.add("四");
let res = queue.getFirst();
```
250.pop()
```
import Queue from "@ohos.util.Queue"
let queue = new Queue();
queue.add("四");
let res = queue.pop();
```
251.forEach()
```
import Queue from "@ohos.util.Queue"
let queue = new Queue();
queue.add(1);
queue.add(2);
queue.add(3);
queue.add(4);
queue.forEach((item, index) => {
    arr.push(item);
});
```
252.[Symbol.iterator]()
```
import Queue from "@ohos.util.Queue"
let queue = new Queue();
queue.add("四");
let itr = queue[Symbol.iterator]();
```
253.isEmpty()
```
import Stack from "@ohos.util.Stack"
let stack = new Stack();
stack.push(8);
stack.push(5);
let res = stack.isEmpty();
```
254.peek()
```
import Stack from "@ohos.util.Stack"
let stack = new Stack();
stack.push(1234);
let res = stack.peek();
```
255.pop()
```
import Stack from "@ohos.util.Stack"
let stack = new Stack();
stack.push(1234);
let res = stack.pop();
```
256.push()
```
import Stack from "@ohos.util.Stack"
let stack = new Stack();
stack.push(12);
```
257.locate()
```
import Stack from "@ohos.util.Stack"
let stack = new Stack();
stack.push("A");
stack.push("B");
stack.push(1);
let res = stack.locate("A");
```
258.forEach()
```
import Stack from "@ohos.util.Stack"
let stack = new Stack();
stack.push(8);
stack.push(5);
stack.push(c);
stack.push(6);
stack.forEach((item, index) => {
    arr.push(item);
});
```
259.[Symbol.iterator]()
```
import Stack from "@ohos.util.Stack"
let stack = new Stack();
stack.push("A");
stack.push("B");
stack.push(1);
let itr = stack[Symbol.iterator]();
```
260.isEmpty()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.isEmpty();
```
261.hasKey()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.hasKey(1);
```
262.hasValue()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.hasValue("a");
```
263.get()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.get(1);
```
264.getFirstKey()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.getFirstKey();
```
265.getLastKey()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.getLastKey();
```
266.setAll()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let treeMap1 = new TreeMap();
treeMap1.set(0, "a");
treeMap1.set(1, "b");
treeMap1.set(2, "c");
treeMap.setAll(treeMap1);
```
267.set()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
```
268.remove()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.remove(1);
```
269.clear()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
treeMap.clear();
```
270.getLowerKey()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.getLowerKey(1);
```
271.getHigherKey()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.getHigherKey(1);
```
272.keys()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.keys();
```
273.values()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.values();
```
274.replace()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
let res = treeMap.replace(1, "B");
```
275.forEach()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
treeMap.set(2, "c");
treeMap.set(3, "d");
treeMap.set(4, "g");
let arr1 = [];
treeMap.forEach((value, key) => {
    arr1.push(value);
});
```
276.entries()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
treeMap.set(2, "c");
let entries = treeMap.entries();
```
277.[Symbol.iterator]()
```
import TreeMap from "@ohos.util.TreeMap"
let treeMap = new TreeMap();
treeMap.set(0, "a");
treeMap.set(1, "b");
treeMap.set(2, "c");
let iters = treeMap[Symbol.iterator]();
```
278.isEmpty()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
let res = treeSet.isEmpty();
```
279.has()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
let res = treeSet.has("c");
```
280.add()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
```
281.remove()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
let res = treeSet.remove("c");
```
282.clear()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
treeSet.clear();
```
283.getFirstValue()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
let res = treeSet.getFirstValue();
```
284.getLastValue()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
let res = treeSet.getLastValue();
```
285.getLowerValue()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add(0);
treeSet.add(1);
treeSet.add(2);
treeSet.add(3);
let res = treeSet.getLowerValue(2);
```
286.getHigherValue()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add(0);
treeSet.add(1);
treeSet.add(2);
treeSet.add(3);
let res = treeSet.getHigherValue(3);
```
287.popFirst()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add(0);
treeSet.add(1);
treeSet.add(2);
treeSet.add(3);
let res = treeSet.popFirst();
```
288.popLast()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add(0);
treeSet.add(1);
treeSet.add(2);
treeSet.add(3);
let res = treeSet.popLast();
```
289.forEach()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add(0);
treeSet.add(1);
treeSet.add(2);
treeSet.add(3);
treeSet.add(4);
let arr1 = [];
treeSet.forEach((value, key) => {
    arr1.push(value);
});
```
290.values()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
let res = treeSet.values();
```
291.entries()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
let res = treeSet.entries();
```
292.[Symbol.iterator]()
```
import TreeSet from "@ohos.util.TreeSet"
let treeSet = new TreeSet();
treeSet.add("a");
treeSet.add("b");
treeSet.add("c");
let res = treeSet[Symbol.iterator]();
```

## 3. js_sys_module子模块
### 3.1. 简介
进程主要用于获取进程的相关ID，获取和修改进程的工作目录，退出和关闭进程。 childprocess 对象可用于创建新进程。 主进程可以获取子进程的标准输入输出，发送信号，关闭子进程。
### 3.2. 目录

```
commomlibrary/ets_utils/js_sys_module/
├── Class:PROCESS                   # PROCESS类
├── Uid                             # Uid属性
├── Gid                             # Gid属性
├── EUid                            # EUid属性
├── EGid                            # EGid属性
├── Groups                          # Groups属性
├── Pid                             # Pid属性
├── Ppid                            # Ppid属性
├── chdir()                         # chdir方法
├── uptime()                        # uptime方法
├── kill()                          # kill方法
├── abort()                         # abort方法
├── on()                            # on方法
├── tid                             # tid方法
├── getStartRealtime()              # getStartRealtime方法
├── getAvailableCores()             # getAvailableCores方法
├── getPastCputime()                # getPastCputime方法
├── isIsolatedProcess()             # isIsolatedProcess方法
├── is64Bit()                       # is64Bit方法
├── isAppUid()                      # isAppUid方法
├── getUidForName()                 # getUidForName方法
├── getThreadPriority()             # getThreadPriority方法
├── getSystemConfig()               # getSystemConfig方法
├── getEnvironmentVar()             # getEnvironmentVar方法
├── exit()                          # exit方法
├── cwd()                           # cwd方法
├── off()                           # off方法
├── runCmd()                        # runCmd方法
└─── Class:CHILDPROCESS             # class of CHILDPROCESS类
    ├── close()                     # close方法
    ├── kill()                      # kill方法
    ├── getOutput()                 # getOutput方法
    ├── getErrorOutput()            # getErrorOutput方法
    ├── wait()                      # wait方法
    ├── killed                      # killed属性
    ├── pid                         # pid属性
    ├── ppid                        # ppid属性
    └── exitCode                    # exitCode属性
|—— Class:CONSOLE
    ├── debug()                     # debug方法
    ├── log()                       # log方法
    ├── info()                      # info方法
    ├── warn()                      # warn方法
    ├── error()                     # error方法
    ├── assert()                    # assert方法
    ├── count()                     # count方法
    ├── countReset()                # countReset方法
    ├── dir()                       # dir方法
    ├── dirxml()                    # dirxml方法
    ├── group()                     # group方法
    ├── groupCollapsed()            # groupCollapsed方法
    ├── groupEnd()                  # groupEnd方法
    ├── table()                     # table方法
    ├── time()                      # time方法
    ├── timeEnd()                   # timeEnd方法
    ├── timeLog()                   # timeLog方法
    ├── trace()                     # trace方法
|—— Class:TIMER
    ├── setInterval()               # setInterval方法
    ├── setTimeout()                # setTimeout方法
    ├── clearInterval()             # clearInterval方法
    ├── clearTimeout()              # clearTimeout方法
```

### 3.3. 说明

#### 3.3.1. 接口说明
| 接口名 | 说明 |
| -------- | -------- |
| const uid :number | 返回进程的数字用户 ID。 |
| const gid :number | 返回进程的数字组 ID。 |
| const euid :number | 返回进程的数字有效用户身份。 |
| const egid :number | 返回 node.js 进程的数字有效组 ID。 |
| const groups :number[] |  返回具有补充组 ID 的数组。 |
| const pid :number | 返回进程的PID。 |
| const ppid :number |  返回当前进程的父进程的PID。 |
| chdir(dir:string) :void | 更改 node.js 进程的当前工作目录。 |
| uptime() :number |  返回当前系统已经运行的秒数。 |
| Kill(pid:number, signal:number) :boolean | 将信号发送到识别的进程PID，true表示发送成功。 |
| abort() :void | 导致 node.js 进程立即退出并生成核心文件。 |
| on(type:string ,listener:EventListener) :void | 用于存储用户触发的事件。 |
| exit(code:number):void | 导致 node.js 进程立即退出。 |
| cwd():string |  返回 node.js 进程的当前工作目录。 |
| off(type: string): boolean | 清除用户存储的事件。 True 表示清算成功。 |
| runCmd(command: string, options?: { timeout : number, killSignal : number \| string, maxBuffer : number }): ChildProcess |通过runcmd，你可以fork一个新进程来运行一个shell并返回childprocess对象。 第一个参数command指的是要运行的shell，第二个参数options指的是子进程的一些运行参数。 这些参数主要是指 timeout、killsignal 和 maxbuffer。 如果设置了timeout，则子进程会在超时后发送killsignal信号。 Maxbuffer 用于限制可以接收的最大 stdout 和 stderr 大小。 |
| wait()： Promise\<number> | 用于等待子进程运行并返回promise对象，其值为子进程的退出码。 |
| getOutput(): Promise\<Uint8Array> |  用于获取子进程的标准输出。 |
| getErrorOutput(): Promise\<Uint8Array> | 用于获取子进程的标准错误输出。 |
| const tid:number | 返回进程的 TID。 |
| getStartRealtime() :number | 获取从系统启动到进程启动所经过的实时时间（以毫秒为单位）。 |
| getAvailableCores() :number[] | 获取多核设备上当前进程可用的 CPU 内核。 |
| getPastCputime() :number | 获取从进程开始到当前时间的 CPU 时间（以毫秒为单位）。 |
| isIsolatedProcess(): boolean | 检查进程是否被隔离。 |
| is64Bit(): boolean | 检查进程是否在 64 位环境中运行。 |
| isAppUid(v:number): boolean | 检查指定的 uid 是否属于特定应用程序。 |
| getUidForName(v:string): number | 根据用户名获取用户所属的用户组ID |
| getThreadPriority(v:number): number | 根据指定的 TID 获取线程优先级。 |
| getSystemConfig(name:number): number | 根据指定的系统配置名称获取系统的配置。 |
| getEnvironmentVar(name:string): string | 根据环境变量的名称获取对应的值。 |
| close(): void | 用于关闭正在运行的子进程。 |
| kill(signal: number \| string): void |  用于向子进程发送信号。 |
| readonly killed: boolean | 表示信号是否发送成功，true表示信号发送成功。 |
| readonly exitCode: number | 表示子进程的退出代码。 |
| readonly pid: number | 表示子进程ID。 |
| readonly ppid: number | 代表主进程ID。 |
| debug(message: string, ...arguments: any[]): void | 打印debug信息。 |
| log(message: string, ...arguments: any[]): void | 打印log信息。 |
| info(message: string, ...arguments: any[]): void | 打印info信息。 |
| warn(message: string, ...arguments: any[]): void | 打印warn信息。 |
| error(message: string, ...arguments: any[]): void | 打印error信息。 |
| assert(value?: Object, ...arguments: Object[]): void | 若value为假，打印后续内容。 |
| count(label?: string): void | 对label名计数。 |
| countReset(label?: string): void | 清除label名的计数。 |
| dir(dir?: Object): void | 打印对象内容。 |
| dirxml(...arguments: Object[]): void | 打印日志。 |
| group(...arguments: Object[]): void | 缩进一组。 |
| groupCollapsed(...arguments: Object[]): void | 缩进一组。 |
| groupEnd(): void | 取消缩进一组。 |
| table(tableData?: Object): void | 以表格形式打印数据。 |
| time(label?: string): void | 开始计时。 |
| timeEnd(label?: string): void | 结束计时。 |
| timeLog(label?: string, ...arguments: Object[]): void | 打印当前计时。 |
| trace(...arguments: Object[]): void | 打印当前栈。 |
|  setInterval(handler: Function \| string, delay: number, ...arguments: any[]): number | 定时调用回调函数。 |
|  setTimeout(handler: Function \| string, delay?: number, ...arguments: any[]): number | 计时结束调用回调函数。 |
|  clearInterval(intervalID?: number): void | 清除定时回调。 |
|  clearTimeout(timeoutID?: number): void | 清除计时回调。 |

#### 3.3.2. 使用说明

各接口使用方法如下：
1.uid()
```
uid(){
    var res =  Process.uid;
}
```
2.gid()
```
gid(){
    var result = Process.gid;
}
```
3.euid()
```
euid(){
    var and = Process.euid;
}
```
4.egid()
```
egid(){
    var resb = Process.egid;
}
```
5.groups()
```
groups(){
    var answer = Process.groups;
}
```
6.pid()
```
pid(){
    var result = Process.pid;
}
```
7.ppid()
```
ppid(){
    var result = Process.ppid;
}
```
8.chdir()
```
chdir(){
    Process.chdir("123456");
}
```
9.uptime()
```
uptime(){
    var num = Process.uptime();
}
```
10.kill()
```
kill(){
    var ansu = Process.kill(5,23);
}
```
11.abort()
```
abort(){
    Process.abort();
}
```
12.on()
```
on(){
    function add(num){
        var value = num + 5;
        return value;
    }
    Process.on("add",add);
}
```
13.exit()
```
exit(){
    Process.exit(15);
}
```
14.Cwd()
```
Cwd(){
    var result = Process.cwd();
}
```
15.off()

```
off(){
    var result =  Process.off("add");
}
```
16.runCmd()
```
runCmd(){
    var child = process.runCmd('echo abc')
    // killSignal can be a number or a string
    var child = process.runCmd('echo abc;', {killSignal : 'SIGKILL'});
    var child = process.runCmd('sleep 5; echo abc;', {timeout : 1, killSignal : 9, maxBuffer : 2})
}
```
17.wait()
```
wait()
{
    var child = process.runCmd('ls')
    var status = child.wait();
    status.then(val => {
        console.log(val);
    })
}
```
18.getOutput()
```
getOutput(){
    var child = process.runCmd('echo bcd;');
    var res = child.getOutput();
    child.wait();
    res.then(val => {
        console.log(val);
    })
}
```
19.getErrorOutput()
```
getErrorOutput(){
    var child = process.runCmd('makdir 1.txt'); // execute an error command
    var res = child.getErrorOutput();
    child.wait();
    res.then(val => {
        console.log(val);
    })
}
```
20.close()
```
close(){
    var child =  process.runCmd('ls; sleep 5s;')
    var result = child.close()
}
```
21.kill()
```
kill(){
    var child =  process.runCmd('ls; sleep 5s;')
    var result = child.kill('SIGHUP');
    child.wait();
    var temp = child.killed;
}
```
22.killed
```
{
    var child = process.runCmd('ls; sleep 5;')
    child.kill(3);
    var killed_ = child.killed;
    child.wait();
}
```
23.exitCode
```
{
    var child = process.runCmd('ls; sleep 5;')
    child.kill(9);
    child.wait();
    var exitCode_ = child.exitCode;
}
```
24.pid
```
pid
{
    var child = process.runCmd('ls; sleep 5;')
    var pid_ = child.pid;
    child.wait();
}
```
25.ppid
```
ppid
{
    var child = process.runCmd('ls; sleep 5;')
    var ppid_ = child.ppid;
    child.wait();
}
```
26.tid
```
tid(){
    var ansu = Process.tid;
}
```
27.isIsolatedProcess()
```
isIsolatedProcess(){
    var ansu = Process.isIsolatedProcess()();
}
```
28.isAppUid()
```
isAppUid(){
    var ansu = Process.isAppUid(10000);
}
```
29.is64Bit()
```
is64Bit(){
    var ansu = Process.is64Bit();
}
```
30.getUidForName()
```
getUidForName(){
    var buf = "root";
    var ansu = Process.getUidForName(buf);
}
```
31.getEnvironmentVar()
```
getEnvironmentVar(){
    var ansu = Process.getEnvironmentVar('USER');
}
```
32.getAvailableCores()
```
getAvailableCores(){
    var ansu = Process.getAvailableCores();
}
```
33.getThreadPriority()
```
getThreadPriority(){
    var result = Process.getTid();
    var ansu = getThreadPriority(result);
}
```
34.getStartRealtime()
```
getStartRealtime(){
    var ansu = Process.getStartRealtime();
}
```
35.getPastCputime()
```
getPastCputime(){
    var ansu = Process.getPastCputime();
}
```
36.getSystemConfig()
```
getSystemConfig(){
    var _SC_ARG_MAX = 0;
    var ansu = Process.getSystemConfig(_SC_ARG_MAX)
}
```
37.console.debug()
```
console.debug("print debug log");
}
```
38.console.log()
```
console.debug("print log");
}
```
39.console.info()
```
console.debug("print info log");
}
```
40.console.warn()
```
console.debug("print warn log");
}
```
41.console.error()
```
console.debug("print error log");
}
```
42.console.assert()
```
for (let number = 2; number <= 5; number++) {
    console.assert(number % 2 === 0, "error");
}
```
43.console.count()
```
console.count("myObj");
```
44.console.countReset()
```
console.count("myObj");
console.countReset("myObj");
```
45.console.dir()
```
function cat(name, age, score){
  this.name = name;
  this.age = age;
  this.score = score;
}
var c = new cat("ohos", 2, [6,8,7]);
console.dir(c);
```
46.console.dirxml()
```
console.xml("print log");
```
47.console.group()
```
console.group();
```
48.console.groupCollapsed()
```
console.groupCollapsed();
```
49.console.groupEnd()
```
console.groupEnd();
```
50.console.table()
```
var languages = {
  csharp: { name: "C#", paradigm: "undefined" },
  fsharp: { name: "F#", paradigm: "functional" }
};
console.table(languages);
```
51.console.time()
```
console.time("timer1");
```
52.console.timeEnd()
```
console.time("timer1");
console.timeEnd("timer1");
```
53.console.timeLog()
```
console.time("timer1");
console.timeLog("timer1");
```
54.console.trace()
```
console.trace();
```
55.setInterval()
```
function callback() {
  console.log("setInterval");
};
setInterval(callback, 100);
```
55.setTimeout()
```
function callback() {
  console.log("setTimeout");
};
setTimeout(callback, 100);
```
55.clearInterval()
```
function callback() {
  console.log("clearInterval");
};
var myVar = setInterval(callback, 1000);
clearInterval(myVar);
```
56.clearTimeout()
```
function callback() {
  console.log("clearTimeout");
};
var myVar = setTimeout(callback, 1000);
clearTimeout(myVar);
```

## 4. js_concurrent_module子模块

### 4.1. 简介

worker能够让js拥有多线程的能力，通过postMessage完成worker线程与宿主线程通信。

### 4.2. 接口说明
接口实现详见：js_concurrent_module/worker

#### 4.2.1. Worker对象描述

宿主线程用于与worker线程通信的Object对象。

##### 4.2.1.1. 接口

1.

- 接口名

|constructor(scriptURL:string, options?:WorkerOptions) | 构造函数 |
|---|---|

- 使用示例

通过判断存放worker.ts的workers目录是否与pages目录同级（以下简称目录同级）和创建项目的模型类别，共有以下四种新建Worker的方式：

(1) FA模型: 目录同级
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker("workers/worker.js", {name:"first worker"});
```
(2) FA模型: 目录不同级（以workers目录放置pages目录前一级为例）
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker("../workers/worker.js", {name:"first worker"});
```
(3)  Stage模型: 目录同级
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker('entry/ets/workers/worker.ts');
```
(4) Stage模型: 目录不同级（以workers目录放置pages目录后一级为例）
```
import worker from "@ohos.worker";
const workerInstance = new worker.Worker('entry/ets/pages/workers/worker.ts');
```
对于Stage模型中scriptURL——"entry/ets/workers/worker.ts"的解释：
- entry: 为module.json5中module中name属性的值；
- ets: 表明当前工程使用的语言；
- worker.ts: 创建worker.ts文件或者worker.js文件都可以。

另外，需在工程的模块级build-profile.json5文件的buildOption属性中添加配置信息，主要分为下面两种情况：

(1) 目录同级(**此情况不添加亦可**)

FA模型:
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/MainAbility/workers/worker.js"
      ]
    }
  }
```
Stage模型:
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/workers/worker.ts"
      ]
    }
  }
```
(2) 目录不同级(**此情况必须添加**)

FA模型:
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/workers/worker.js"
      ]
    }
  }
```
Stage模型(workers目录放在pages目录里为例):
```
  "buildOption": {
    "sourceOption": {
      "workers": [
        "./src/main/ets/pages/workers/worker.ts"
      ]
    }
  }
```
2.

- 接口名

| postMessage(message:Object, options?:PostMessageOptions)  | 向worker线程发送消息  |
|---|---|
| postMessage(message:Object, transfer:ArrayBuffer[])  | 向worker线程发送消息  |

- 使用示例

```
// 示例一
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// 示例二
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
var buffer = new ArrayBuffer(8);
worker.postMessage(buffer, [buffer]);
```

3.

- 接口名

| on(type:string, listener:EventListener)  | 向worker添加一个事件监听  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.on("alert", (e)=>{
     console.log("worker on...");
});
```

4.

- 接口名

| once(type:string, listener:EventListener)  | 向worker添加一个事件监听, 事件监听只执行一次便自动删除  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.once("alert", (e)=>{
    console.log("worker once...");
});
```

5.

- 接口名

| off(type:string, listener?:EventListener)  | 删除worker的事件监听  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.off("alert");
```

6.

- 接口名

| terminate()  | 关闭worker线程，终止worker发送消息  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.terminate();
```

7.

- 接口名

| removeEventListener(type:string, listener?:EventListener)  | 删除worker的事件监听  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.removeEventListener("alert", (e)=>{
    console.log("worker removeEventListener...");
});
```

8.

- 接口名

| dispatchEvent(event: Event)  | 分发定义在worker的事件  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.dispatchEvent({type:"alert"});
```

9.

- 接口名

| removeAllListener()  | 删除worker的所有事件监听  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.removeAllListener();
```

##### 4.2.1.2. 属性

1.

- 属性名

| onexit?:(code:number)=>void  | worker退出时被调用的事件处理程序，处理程序在宿主线程中执行  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onexit = function(e) {
    console.log("onexit...");
}
```

2.

- 属性名

| onerror?:(ev:ErrorEvent)=>void  | worker在执行过程中发生异常被调用的事件处理程序，处理程序在宿主线程中执行  |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onerror = function(e) {
    console.log("onerror...");
}
```

3.

- 属性名

| onmessage?:(ev:MessageEvent)=>void  | 宿主线程收到来自其创建的worker通过parentPort.postMessage接口发送的消息时被调用的事件处理程序， 处理程序在宿主线程中执行 |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onmessage = function(e) {
    console.log("onmessage...");
}
```

4.

- 属性名

| onmessageerror?:(event:MessageEvent)=>void  | worker对象接收到一条无法序列化的消息时被调用的事件处理程序， 处理程序在宿主线程中执行 |
|---|---|

- 使用示例

```
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.onmessageerror = function(e) {
    console.log("onmessageerror...");
}
```

#### 4.2.2. parentPort对象描述

worker线程用于与宿主线程通信的Object对象。

##### 4.2.2.1. 接口

1.

- 接口名

| postMessage(message:Object, options?:PostMessageOptions)  | 向宿主线程发送消息 |
|---|---|
| postMessage(message:Object, transfer:ArrayBuffer[])  | 向宿主线程发送消息  |

- 使用示例

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessage = function(e) {
    parentPort.postMessage("hello world from worker.js");
}
```

2.

- 接口名

| close()  | 关闭worker线程，终止worker接收消息  |
|---|---|

- 使用示例

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessage = function(e) {
    parentPort.close();
}
```

##### 4.2.2.2. 属性

1.

- 属性名

| onmessage?:(event:MessageEvent)=>void  | 宿主线程收到来自其创建的worker通过worker.postMessage接口发送的消息时被调用的事件处理程序，处理程序在worker线程中执行  |
|---|---|

- 使用示例

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessage = function(e) {
    console.log("receive main.js message");
}
```

2.

- 属性名

| onerror?:(ev: ErrorEvent)=>void  | worker在执行过程中发生异常被调用的事件处理程序，处理程序在worker线程中执行  |
|---|---|

- 使用示例

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onerror = function(e) {
    console.log("onerror...");
}

```

3.

- 属性名

| onmessageerror?:(event: MessageEvent)=>void  | worker对象接收到一条无法被反序列化的消息时被调用的事件处理程序， 处理程序在worker线程中执行  |
|---|---|

- 使用示例

```
// main.js
import worker from "@ohos.worker"
const worker = new worker.Worker("workers/worker.js");
worker.postMessage("hello world");

// worker.js
import worker from "@ohos.worker"
const parentPort = worker.parentPort;
parentPort.onmessageerror = function(e) {
    console.log("onmessageerror...");
}
```

### 4.3. 涉及仓

[arkcompiler_ets_runtime](https://gitee.com/openharmony/arkcompiler_ets_runtime/blob/master/README_zh.md)
[arkui_ace_engine](https://gitee.com/openharmony/arkui_ace_engine/blob/master/README_zh.md)
[arkui_napi](https://gitee.com/openharmony/arkui_napi/blob/master/README_zh.md)


# 相关仓

[ets_utils子系统](https://gitee.com/openharmony/commonlibrary_ets_utils/blob/master/README.md)