一些JS的面向对象模式

1.组合使用构造函数模式和原型模式

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function Person(name , age , job){ 	//构造函数模式定义实例的自有属性
	this.name = name;
	this.age = age;
	this.job = job;
	this.friends = ["Shelby", "Court"]
}

Person.prototype = {								//原型模式定义方法和共享属性
	constructor : Person,
	sayName : function(){
		alert(this.name);
	}
}

2.动态原型模式

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function Person(name , age , job){ 	
	this.name = name;
	this.age = age;
	this.job = job;
	if (typeof this.sayName != "function"){//动态添加原型方法，首次调用实例化时添加
    Person.prototype.sayName = function(){
    	alert(this.name);
    }
  }
}

3.寄生构造模式

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function Person(name , age , job){ 	
  var o = new Object();
	o.name = name;
	o.age = age;
	o.job = job;
	o.sayName = function(){
    alert(this.name);
  }
  return o;
}
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function SpecialArray(){
  var values = new Array();
  values.push.apply(values,arguments);
  values.toPipedString = function(){
    return this.join("|");
  };
  return values;
}
var colors = new SpecialArray("red","blue","green");
console.log(colors.toPipedString());

4.稳妥构造函数模式

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function Person(name , age , job){ 	
  var o = new Object();
	o.sayName = function(){
    alert(name);
  }
	o.changeName = function(newName){
    name = newName;
  }
  return o;
}

var friend = Person("Nicholas",29,"Software Engineer");
friend.sayName(); //alert "Nicholas"
console.log(friend.name); //shows "undefined"
friend.changeNmae("lwflky"); 
friend.sayName(); //alert "lwflky"
console.log(friend.name); //still shows "undefined"

这种模式除了自身的方法，没有其他办法修改实例的属性值