Comments on: Passing arguments to javascript’s setTimeout() method using closures

By: Trev

Trev — Tue, 01 Dec 2009 12:32:32 +0000

Another version that seems to work is simply: setTimeout("doAlert("+msg+")", 1); Might get a bit confusing with multiple arguments mind you, but works in IE8, FF3 and Chrome (so presumably also in Safari). Not got IE7 to test it on however.

By: archerid

archerid — Thu, 27 Aug 2009 20:40:52 +0000

This was incredibly helpful. I’ve spent an embarrassingly long time trying to track down the right way to pass params through setTimeout. Thanks for posting your method.

By: John

John — Fri, 06 Feb 2009 17:25:33 +0000

Follow-up:

Well, it seems as though you’re right and wrong Thomas. Firefox does subscribe to what appears to be the standard

https://developer.mozilla.org/En/DOM/Window.setTimeout

but IE, of course does not. Thomas’ syntax doesn’t work on IE7 (I tried it).

An alternative–but less elegant–solution that works in both browsers is to frame the called function/parameters in quotes, thus:

function called(a,b) {
alert(a+”-”+b)
}
function caller(a,b) {
setTimeout(‘called(‘+a+’,'+b+’)',2000);
}

Later code ….
caller(1,2);caller(3,4)
Will show alerts of “1-2″ and “3-4″ after 2 seconds.

By: John

John — Fri, 06 Feb 2009 07:47:50 +0000

Good comment by Thomas and while I accept your authority on this you’re about the only person out there defining the call this way. Most of the examples I’ve seen pass a “call to the function” and do so in quotes! ie:

setTimeout(‘someFunction()’,etc)

And one reference (I can’t remember where) defines that third parameter as an optional definition of the language of the called function!

Your solution works, of course.

By: Thomas

Thomas — Mon, 15 Dec 2008 20:11:55 +0000

There’s an easier way to do this:

... var msg = "Hello World";


setTimeout(doAlert, 1, [msg]);

...

function doAlert(msg) { alert(msg); }

There’s no need for the delay function.

Furthermore, when passing a reference to a function as the first parameter to the setTimeout method, you’re supposed to pass the reference to the function, not a call to the function.

e.g.
// passing a call to the function is incorrect var t = setTimeout(someFunction(), 1, argsArray);

vs.

// passing a *reference* to the function is correct var t = setTimeout(someFunction, 1, argsArray);

Enjoy,

Thomas