Window.setInterval( ) method used to execute specified code periodically.
setInterval() Method Syntax
We can use either of the following syntaxes.
The first syntax:
Where code is a string of JS code that you want to execute periodically. Make sure to add semicolons to separate multiple statements.
interval is an integer value in milliseconds.
The second syntax:
window.setInterval(function, interval, args...);
Where function(required) is nothing but JS code as a function. IE 4 and earlier versions don’t support this parameter.
In args parameters(optional) we can pass any number of parameters. Not supported in IE 9 and earlier versions.
What does it return?
Well the periodic execution has to stop. So, it returns a value that we can pass to Window.clearInterval( ) which then can be used to cancel the periodic execution of the supplied code or function.
setInterval() method Examples
This example prints yogeshchauhan.com every 3 seconds:
Let’s modify the example above to print the time as well. It will add the time to the string yogeshchauhan.com every 3 seconds.
How to stop setInterval() execution?
As we saw earlier, we can use clearInterval() to stop the execution.
Let’s use the same example to stop the execution.
We must use a variable when creating the interval method to stop the execution using the clearInterval() method.
Let’s create a variable in the same example above and add a stop button to stop the execution.
I used setInterval() and clearInterval() to create a progress bar in this post.
How to pass parameters in setInterval()?
Let’s pass few parameters in the example above.