delay/sleep in javascript?

Question

Is there a simple way to pause the script in Javascript? I'm looking for the javascript equivalent of time.sleep(1) in Python. I do NOT want setTimeout(continueExecution, 10), or anything with getTime. Can this be done?

EDIT: It wasn't quite as easy, but I think I can get it done with setTimeout

Answer 1

JavaScript is usually ran in a single thread using an event-loop. This is why you can't do any "Thread.sleep". If you could it would freeze everything else for that duration and believe me you don't want to do that. This is why almost everything in JavaScript runs using non-blocking IO and that's why the only way you can do delay execution is by using setTimeout or setInterval.

Answer 2

without setTimeout, you could always loop until you reach a desired date time:

Disclaimers: This is untested. Since javascript is single-threaded, this WILL freeze your entire browser while looping. See other questions for more information on this topic.

var delay = 5; // 5 second delay
var now = new Date();
var desiredTime = new Date().setSeconds(now.getSeconds() + delay);

while (now < desiredTime) {
    now = new Date(); // update the current time
}

// continue execution

Answer 3

If you are using jQuery 1.5+ you can make a really simple plugin (i

(function($) {
    $.wait = function(time) {
         return $.Deferred(function(dfd) {
               setTimeout(dfd.resolve, time); // use setTimeout internally. 
         }).promise();
    }
}(jQuery));

Then use it like this:

$.wait(3000).then(function(){ 
   ....
});

And it will launch your function after waiting 3 seconds. It use setTimeout internally, but that's the only way to do it in JavaScript.