js閉包，圓形，物件

瓜瓜東西發表於2014-09-03
JS物件
5  js物件導向的思想--閉包，圓形，物件
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<script type="text/javascript">
//三種變數 三種方法
	function Person1(){
		var name="wiki";
		this.name2 = "wiki2";
		
		function m1(){
			alert("m1");
		}
		this.m2=function(){
			alert("m2");
			m1();
		};
		
	}
	Person1.ourname="wiki3";
	Person1.m3=function(){
		alert("m3");
	}
	var p = new Person1();
/* 	alert(p.name);
	alert(p.name2);
	alert(Person1.ourname); */
	
	/*p.m1();*/ 
	/* p.m2();
	Person1.m3();  */
	
	
	//動態新增刪除物件
	p.v1="v1";
	p.v2=function(){
		alert("v2");
	};
/* 	alert(p.v1);
	p.v2();
	delete p.v1;
	delete p.v2;
	alert(p.v1);
	p.v2();//沒有回出錯 */
	
	
	
	//this動態指向 --this指定什麼就算什麼
	var names = "wiki";
	function say(){
		alert(this.names);
	}
	
	var car = {names:"hello",say:say};
/* 	say();
	car.say();
	car.say.apply(window); */
	
	
	
	//圓形問題
	function Person2(){};
	var p2 = new Person2();
	/* alert(Person2.prototype);
	alert(Person2.prototype.constructor);
	alert(p2.prototype); */
	//原型繼承例項
	
	function Person3(name){
		this.name=name;
		this.say=function(){
			return this.name;
		};
	};
	function Child(){
		
	}
	Child.prototype=new Person3("i am a person");
	
	var child = new Child();
	alert(child.say());
	
	//閉包例項 +方法加方法必須返回裡面的方法名，否則語法錯誤
	//閉包使得變數永久儲存於記憶體中
	function Person4(){
		var n=998;
		function getN(){
			n++;
			alert(n);
		};
		function getM(){
			alert(n+"11");
		};
		return getN;
	}
	
	var result = Person4();
	result();
	result();
	
	
	
	
</script>
</head>
<body>

</body>
</html>

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