javascript syntax and jQuery source

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For the function (function($){})(), I’ve seen it with the word jQuery in it, why is that?

Can someone explain the following syntax that is used in the jQuery source files? I am learning jQuery and trying to dive into writing a jquery.ui.widget.

(function ($)
{
    ... code ...
} (jQuery));

While I am using jQuery, this is really just a JavaScript question, I guess.

Thanks, Craig

See a similar question from yesterday: http://stackoverflow.com/questions/3090284/for-the-function-function-ive-seen-it-with-the-word-jquery-in-it-why — Christian C. Salvadó, Jun 23 '10 at 20:14
Indeed JavaScript-related, see http://stackoverflow.com/questions/1643321/javascript-why-the-anonymous-function-wrapper among many others. — Marcel Korpel, Jun 23 '10 at 20:15

score 7 · Accepted Answer · answered Jun 23 '10 at 20:14

7

This defines an anonymous function with one argument, called $, then invokes the function passing jQuery as the argument.

answered Jun 23 '10 at 20:14

Ned Batchelder

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score 1 · Answer 2 · answered Jun 23 '10 at 20:15

It's called the self executing anonymous function. No different than any other function call except the function is a literal ( doesnt have a name ), is wrapped in parens to make it a valid expression and then invoked.

function blah($){};
blah(jQuery);

is the same as that piece of code, it creates a private namespace in which the window.jQuery object is passed and referenced within the function body as $ to prevent namespace collisions.

score 1 · Answer 3 · answered Jun 23 '10 at 20:24

1

This is an example of the JavaScript module pattern.

answered Jun 23 '10 at 20:24

Scott Bale

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javascript syntax and jQuery source

3 Answers3