Comments on: jQuery.isFunction()

By: Kyle Florence

Kyle Florence — Thu, 13 Jan 2011 01:56:02 +0000

In certain situations in some browsers, things are incorrectly returned as the "function" type, or things that are in fact functions are returned as another type. There are several test cases you can see here: https://github.com/jquery/jque...

One example:

var obj = document.createElement("object");

// Firefox says this is a function
typeof obj; // => "function"

Keep in mind these are mostly edge cases, but the reason $.isFunction was made was simply to be positive about something being a function (which can be quite important for the jQuery library itself, maybe not so much for your code).

By: Michal Čizmazia

Michal Čizmazia — Wed, 22 Sep 2010 13:42:11 +0000

Could you provide a brief explanation of the difference between $.isFunction(f) and typeof f === “function”?

By: Michal Čizmazia

Michal Čizmazia — Wed, 22 Sep 2010 05:42:11 +0000

Could you provide a brief explanation of the difference between $.isFunction(f) and typeof f === “function”?

By: bx166er

bx166er — Fri, 21 May 2010 12:20:07 +0000

Here's another example...
If I have a function like this:


jQuery.loadImages = function() {   ... function here ...  };

Then to test whether the jquery function exists, i would use:


if(jQuery.isFunction(jQuery.loadImages)) {alert('yes');} else alert('no');