jQuery命名空间无冲突

var
2     // Map over jQuery in case of overwrite
3     _jQuery = window.jQuery,
4
5     // Map over the $ in case of overwrite
6     _$ = window.$;
7
8 jQuery.noConflict = function( deep ) {
9     if ( window.$ === jQuery ) {
10         window.$ = _$;
11     }
12
13     if ( deep && window.jQuery === jQuery ) {
14         window.jQuery = _jQuery;
15     }
16
17     return jQuery;
18 };