Alert "Hello" every 3 seconds (3000 milliseconds):
More "Try it Yourself" examples below.
The setInterval() method calls a function or evaluates an expression at specified intervals (in milliseconds).
The setInterval() method will continue calling the function until clearInterval() is called, or the window is closed.
The ID value returned by setInterval() is used as the parameter for the clearInterval() method.
Tip: 1000 ms = 1 second.
Tip: To execute a function only once, after a specified number of milliseconds, use the setTimeout() method.
The numbers in the table specify the first browser version that fully supports the method.
|function||Required. The function that will be executed|
|milliseconds||Required. The intervals (in milliseconds) on how often to execute the code|
|param1,param2,...||Optional. Additional parameters to pass to the function (Not supported in IE9 and earlier)|
|Return Value:||A Number, representing the ID value of the timer that is set. Use this value with the clearInterval() method to cancel the timer|
You can also refer to a "named" function; Alert "Hello" every 3 seconds (3000 milliseconds):
Display the current time (the setInterval() method will execute the function once every 1 second, just like a digital watch):
Using clearInterval() to stop time in the previous example:
Toggle between two background colors once every 300 milliseconds:
Pass parameters to the alertFunc function (does not work in IE9 and earlier):
However, if you use an anonymous function, it will work in all browsers:
Window Object: clearInterval() Method
Window Object: setTimeout() Method
Window Object: clearTimeout() Method