1# @ohos.systemCapability (System Capability) (System API) 2 3System capability (SysCap) refers to a relatively independent feature in the operating system. Different devices provide different system capabilities, and multiple APIs implement a system capability. You can determine whether an API can be used based on system capabilities. This module provides APIs for querying the set of system capabilities. 4 5> **NOTE** 6> 7> - The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8> - The APIs provided by this module are system APIs. 9 10 11## Modules to Import 12 13```ts 14import systemcapability from '@ohos.systemCapability'; 15``` 16 17## systemcapability.querySystemCapabilities 18 19querySystemCapabilities(callback: AsyncCallback<string>): void; 20 21Queries system capabilities. This API uses an asynchronous callback to return the result. 22 23**System capability**: SystemCapability.Developtools.Syscap 24 25**Parameters** 26 27| Name| Type| Mandatory| Description| 28| -------- | -------- | -------- | -------- | 29| callback | AsyncCallback<string> | Yes| Callback used to return the result.| 30 31 32**Example** 33 34```ts 35try { 36 systemcapability.querySystemCapabilities((err:Error, data:string) => { 37 if (err == undefined) { 38 console.log("get system capabilities:" + data) 39 } else { 40 console.log(" get system capabilities err:" + err) 41 }}); 42}catch(e){ 43 console.log("get unexpected error: " + e); 44} 45``` 46 47 48## systemcapability.querySystemCapabilities 49 50querySystemCapabilities(): Promise<string> 51 52Queries system capabilities. This API uses a promise to return the result. 53 54**System capability**: SystemCapability.Developtools.Syscap 55 56**Return value** 57 58| Type| Description| 59| -------- | -------- | 60| Promise<string> | Promise used to return the result.| 61 62**Example** 63 64```ts 65try { 66 systemcapability.querySystemCapabilities().then((value:string) => { 67 console.log("get system capabilities: " + value); 68 }).catch((err:Error) => { 69 console.log("get system capabilities error: " + err); 70 }); 71}catch(e){ 72 console.log("get unexpected error: " + e); 73} 74``` 75 76 77> **NOTE** 78> 79> The system capabilities returned by the preceding APIs are in the form of an encoded numeric string. 80