# Timer The **Timer** module provides basic timer capabilities. You can use the APIs of this module to execute functions at the specified time. > **NOTE** > > The initial APIs of this module are supported since API version 3. Newly added APIs will be marked with a superscript to indicate their earliest API version. ## setTimeout setTimeout(handler: Function | string, delay?: number, ...arguments: any[]): number Sets a timer for the system to call a function after the timer goes off. **System capability**: SystemCapability.ArkUI.ArkUI.Full **Parameters** | Name| Type| Mandatory| Description| | -------- | -------- | -------- | -------- | | handler | Function \| string | Yes| Function to be called after the timer goes off.| | delay | number | No| Number of milliseconds delayed before the execution. If this parameter is left empty, the default value **0** is used, which means that the execution starts immediately or as soon as possible.| | ...arguments | Array<any> | No| Additional parameters to pass to the handler after the timer goes off.| **Return value** | Type| Description| | -------- | -------- | | number | Timer ID.| **Example** ```js export default { setTimeOut() { var timeoutID = setTimeout(function() { console.log('delay 1s'); }, 1000); } } ``` ## clearTimeout clearTimeout(timeoutID: number): void Cancels the timer created via **setTimeout()**. **System capability**: SystemCapability.ArkUI.ArkUI.Full **Parameters** | Name| Type| Mandatory| Description| | -------- | -------- | -------- | -------- | | timeoutID | number | Yes| ID of the timer to cancel, which is returned by **setTimeout()**| **Example** ```js export default { clearTimeOut() { var timeoutID = setTimeout(function() { console.log('do after 1s delay.'); }, 1000); clearTimeout(timeoutID); } } ``` ## setInterval setInterval(handler: Function | string, delay: number, ...arguments: any[]): number Sets a repeating timer for the system to repeatedly call a function at a fixed interval. **System capability**: SystemCapability.ArkUI.ArkUI.Full **Parameters** | Name| Type| Mandatory| Description| | -------- | -------- | -------- | -------- | | handler | Function \| string | Yes| Function to be called repeatedly.| | delay | number | Yes| Number of milliseconds delayed before the execution.| | ...arguments | Array<any> | No| Additional parameters to pass to the handler after the timer goes off.| **Return value** | Type| Description| | -------- | -------- | | number | ID of the repeating timer.| **Example** ```js export default { setInterval() { var intervalID = setInterval(function() { console.log('do very 1s.'); }, 1000); } } ``` ## clearInterval clearInterval(intervalID: number): void Cancels the repeating timer set via **setInterval()**. **System capability**: SystemCapability.ArkUI.ArkUI.Full **Parameters** | Name| Type| Mandatory| Description| | -------- | -------- | -------- | -------- | | intervalID | number | Yes| ID of the repeating timer to cancel, which is returned by **setInterval()**.| **Example** ```js export default { clearInterval() { var intervalID = setInterval(function() { console.log('do very 1s.'); }, 1000); clearInterval(intervalID); } } ```