apply和call改变作用域

 1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 2     <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
 3     <head>
 4         <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
 5         <title>改变作用域</title>        
 6         <script type="text/javascript">            
 7             var o1={ handle:'xxxx'};
 8             function whoAmI(){
 9                 return this.handle;
10             }
11             o1.identifyMe=whoAmI;
12             console.log(o1.identifyMe());
13             console.log(whoAmI.call(o1));
14             console.log(whoAmI.apply(o1));            
15         </script>
16     </head>
17     <body>        
18     </body>
19     </html>

通过apply或者call改变作用域，三者的结果是一样的，都会输出xxxx