javascript中调用上下文信息的方法

一.使用函数自身

 <script type="text/javascript">
2  function oFunc(){
3    alert(oFunc.toString());
4  };
5  oFunc();
6 </script>

 

二.使用函数caller属性

其表示调用当前函数的上层函数。

 1 <script type="text/javascript">
 2     function WhoCallMe(){
 3         alert("My caller is "+WhoCallMe.caller);
 4     };
 5     function CallerA(){WhoCallMe();};
 6     function CallerB(){WhoCallMe();};
 7 
 8     WhoCallMe();//My caller is null
 9     CallerA();//my caller is function CallerA(){WhoCallMe();};
10     CallerB();//my caller is function CallerB(){WhoCallMe();};
11 </script>

 三.使用this

 1 <script type="text/javascript">
 2     function WhoAmI(){
 3         alert("I'm "+this.name+" of "+typeof(this));
 4     };
 5     WhoAmI();
 6 
 7     var SteveJobs = {name:"Steve Jobs"};
 8     SteveJobs.WhoAmI=WhoAmI;
 9     SteveJobs.WhoAmI();//this是Steve Jobs
10 
11     var BillGates = {name:"Bill Gates"};
12     BillGates.WhoAmI=WhoAmI;
13     BillGates.WhoAmI();//this是Bill Gates
14 
15 </script>

 

四.使用Call

 1 <script type="text/javascript">
 2     function WhoAmI(){
 3         alert("I'm "+this.name+" of "+typeof(this));
 4     };
 5     WhoAmI();
 6 
 7     var SteveJobs = {name:"Steve Jobs"};
 8     
 9     var BillGates = {name:"Bill Gates"};
10 
11     WhoAmI.call(SteveJobs);//输出I'm Steve Jobs of Object
12     WhoAmI.call(BillGates);//输出I'm Bill Gates of Object
13     
14 </script>