Not off topic at all, I'll bet a lot of people wonder about that.
The short answer is that you are creating a function and calling it
immediately. You pass in jQuery as an argument which goes into the function
parameter named $, so that's how $ gets to be a reference to the jQuery
object.
Let's break it down. First, as you know, $ is simply another letter as far
as JavaScript identifiers are concerned - there's no magic about that
particular character, so $ is just a function or variable name like any
other. You could call it JQ instead of $ and the same principles would
apply.
So, start with this:
(function( $ ) {
alert( $ === jQuery ); // "true"
})( jQuery );
Now, pull out the inline anonymous function and make it a named function:
function foobar( $ ) {
alert( $ === jQuery ); // "true"
}
(foobar)( jQuery );
We don't need those odd parentheses any more (they were required for
syntactic reasons with the inline function):
function foobar( $ ) {
alert( $ === jQuery ); // "true"
}
foobar( jQuery );
Look more familiar now?
-Mike
> Slightly off topic question...
>
> What exactly does (function($){ ... })(jQuery) do?
>
> How does it work?
>
> I understand what it basically does, how it treats $ like
> jQuery, but how does that notation do that, exactly?
