Javascript

1. function gEval(){
2.     (function (){
3.         var a = 'local';
4.         jQuery.globalEval('var a = "global";');
5.         eval('var b = "global"');
6.     })();
7. }
8.  
9. gEval();
10.  
11.  
12. $('.jqTest :button').on('click', function(e){
13.     alert(a);
14.     alert(b);//Uncaught ReferenceError: b is not defined
15. });

HTML

1. <div class="jqTest">
2.     <input type="button" value="execute" id="execute" />
3. </div>