What's the equivalent of Java's Thread.sleep() in Javascript?

Question

What's the equivalent of Java's Thread.sleep() in Javascript?

Answer 1

You can either write a spin loop (a loop that just loops for a long period of time performing some sort of computation to delay the function) or use:

setTimeout("Func1()", 3000);

This will call 'Func1()' after 3 seconds.

Edit:

Credit goes to the commenters, but you can pass anonymous functions to setTimeout.

setTimeout(function() {
   //Do some stuff here
}, 3000);

This is much more efficient and does not invoke javascript's eval function.

Answer 2

There's no direct equivalent, as it'd pause a webpage. However there is a setTimeout(), e.g.:

function doSomething() {
  thing = thing + 1;
  setTimeout(doSomething, 500);
}

Closure example (thanks Daniel):

function doSomething(val) {
  thing = thing + 1;
  setTimeout(function() { doSomething(val) }, 500);
}

The second argument is milliseconds before firing, you can use this for time events or waiting before performing an operation.

Edit: Updated based on comments for a cleaner result.

Answer 3

The simple answer is that there is no such function.

The closest thing you have is:

var millisecondsToWait = 500;
setTimeout(function() {
    // Whatever you want to do after the wait
}, millisecondsToWait);

Note that you especially don't want to busy-wait (e.g. in a spin loop), since your browser is almost certainly executing your JavaScript in a single-threaded environment.

Here are a couple of other SO questions that deal with threads in JavaScript:

• http://stackoverflow.com/questions/30036/javascript-and-threads
• http://stackoverflow.com/questions/39879/why-doesnt-javascript-support-multithreading

And this question may also be helpful:

• http://stackoverflow.com/questions/797115/javascript-settimeout-without-putting-code-into-a-string

Answer 4

Or maybe you can use the setInterval function, to call a particular function, after the specified number of milliseconds. Just do a google for the setInterval prototype.I don't quite recollect it.