note(4)

<script type="text/javascript" >
     var name = '高伟刚';  
	 var person = {
	    name : 'gao',
		sayName : function(){
		    alert(this.name);
		}
	 };
	 var p = person.sayName;//this的值不能维持，改为指向window
	 p();//'高伟刚'
	 person.sayName();//'gao'，this指向person对象
	 
	 /*由上面的可以推倒出下面的结果*/
	 (person.sayName = person.sayName)();//'高伟刚'
	 (person.sayName = function(){
	     alert(this.name);
	 })();//'高伟刚'
</script>