How is the “jQuery” var a function and an object?

Question

For example, when you use jQuery(\'someDiv\');, it\'s a function, but you can also use jQuery.ajax(...);.

How is it possible?

Answer 1

I believe the .ajax example is utilizing the jQuery plug-in architecture. I think the AJAX capabilities of jQuery are just one of the many plug-ins you could use.

The '$' that use see is also just a alias for calling the jQuery.

One last observation jQuery is defined as (from the jquery-1.4.2.js):

var jQuery = function( selector, context ) {
        // The jQuery object is actually just the init constructor 'enhanced'
        return new jQuery.fn.init( selector, context );
    },

and Ajax looks like:

jQuery.extend({
...some other goodness...
ajax: function( origSettings ) 
...more goodness...
});