Javascript - jQuery Core

(function (window, undefined)
{
    var jQuery = (function ()
    {
        var jQuery = function (selector, context)
        {
            return new jQuery.fn.init(selector, context);
        };
        jQuery.fn = jQuery.prototype =
        {
            init: function (selector, context) { }
        };
        //jQuery.fn.init.prototype = jQuery.fn = jQuery.prototype
        jQuery.fn.init.prototype = jQuery.fn;
        jQuery.extend = jQuery.fn.extend = function ()
        {
            // the “this” will vary
        };
        return (window.jQuery = window.$ = jQuery);
    })();
    jQuery.extend({});
    jQuery.fn.extend({});
})(window);

// They are same
$.fn.lgh = function () { return “$.fn.lgh”; };
$.fn.extend({ lgh: function () { return “$.fn.lgh”; } });