Window setTimeout() Method

JavaScript Window Object

setTimeout()method to set a timer, which will call the function or execute the code block once the timer expires.

This method returns a unique identifier for the timer's timeout ID, so you can later callclearTimeout()to delete it.

UseclearTimeout()method to prevent the function from running.

This function executes only once. If you need to execute it repeatedly, please usesetInterval()Method.

Syntax:

window.setTimeout(function, delay, param1,　param2, ...)

setTimeout(function() { alert("Hello World"); },　2000);

Browser compatibility

The numbers in the table specify the first browser version that fully supports the setTimeout() method:

Parameter values

Technical details

More examples

This example references an external "named" function:

var timeoutID;
function myFunc() {
　　timeoutID = setTimeout(myCallback,　2000);
}
function myCallback() {
　　alert("Hello World");
}

Prevent the function from running using clearTimeout():

var timeoutID;
function myFunc() {
　　timeoutID = setTimeout(myCallback,　2000);
}
function myCallback() {
　　alert("Hello World");
}
function myStopFunc() {
　　　clearTimeout(timeoutID);
}

Display the current time recursively (like a digital watch, every1Execute the "startTimer()" function once per second):

window.addEventListener("load", startTimer);
function startTimer() {
　　　var date = new Date();
　　　var x = document.getElementById("result");
　　　x.innerHTML = date.getHours()　+　":"　+　date.getMinutes()　+　":"　+　date.getSeconds();
　　　setTimeout(startTimer,　1000);　　　//　Recursion　
}

Create a dynamic progress bar using setTimeout():

var i = 0;
var bar = document.getElementById("progress",-bar);
var t;
function start() {
　　if(i <　100) {
　i++;
　bar.style.width = i　+　"%";
　bar.innerHTML = i　+　"%";
　t = setTimeout(start,　60);　　//　Recursion
　　}
}
function stop() {
　　clearTimeout(t);
}

Click the "Start Counting" button below to start the timer. Click the "Stop Counting" button to stop counting:

Pass parameters to the myFunc function (in IE9and does not work in earlier versions):

var timeoutID = setTimeout(myFunc,　2000, "First", "Second", "Third");

However, if you use an anonymous function, it will work in all browsers:

var timeoutID = setTimeout(function() { myFunc("First", "Second", "Third"); },　2000);

Related References

Window (Window) Reference:clearTimeout() method

Window (Window) Reference:setInterval() method

Window (Window) Reference:clearInterval() method

JavaScript Window Object