JavaScript面向对象:创建对象

1.初级创建对象

    var oCar=new Object;
	oCar.color='red';
	oCar.door=4;
	oCar.map=3;
	oCar.showColor=function () {
		// body...
		alert(this.color);
	}
	console.log(oCar);

缺点:需要创建多个Car实例

2.工厂函数创建对象

   function showColor(){
		alert(this.color)
	}
	function createCar(sColor,iDoors,iMpg) {
		var oTempCar=new Object;
		oTempCar.color=sColor;
		oTempCar.door=iDoors;
		oTempCar.mpg=iMpg;
		oTempCar.showColor=showColor;
		return oTempCar;
	}
	var oCar1=createCar('red',2,23);
	oCar1.showColor();

 缺点:看起来不像是对象的方法

3.构造函数创建对象

    function Car(sColors,iDoors,iMpg) {
		// body...
		this.color=sColors;
		this.iDoors=iDoors;
		this.iMpg=iMpg;
		this.showColor=function(){
			alert(this.color);
		}
	}

	var oCar1=new Car('red',4,23);
	var oCar2=new Car('blue',5,24)

 优点:内部不需要创建对象,this直接可以访问; 缺点:会重复生成函数

4.原型方式创建对象

   function Car() {
		// body...
	}
	Car.prototype.color='red';
	Car.prototype.doors=4;
	Car.prototype.mpg=23;
	Car.prototype.drivers=['wang','xia'];
	Car.prototype.showColor=function(){
		alert(this.color);
	}

	var oCar1=new Car();
	var oCar2=new Car();

	oCar1.drivers.push('yun');

	console.log(oCar2.drivers);

缺点:没有参数,属性指向对象,对象共享,Car1修改,Car2也会跟着修改

5.混合构造/原型方式

   function  Car(sColor,iDoor,iMpg) {
		this.color=sColor;
		this.doors=iDoor;
		this.mpg=iMpg;
		this.drivers=new Array("Mike","Sue");
	}

	Car.prototype.showColor=function(){
		alert(this.color)
	}

	var oCar1=new Car('red',4,23);
	var oCar2=new Car('blue',5,24);

	oCar1.drivers.push('yun');
	console.log(oCar1.drivers);
    console.log(oCar2.drivers);

构造函数定义非函数属性;原型定义函数属性

6.动态原型方式

   function Car(sColor,iDoor,iMpg){
		this.color=sColor;
		this.door=iDoor;
		this.mpg=iMpg;
		this.driver=new Array('Mike','Sue');

		if(typeof Car._initialized=="undefined"){
			Car.prototype.showColor=function(){
				alert(this.color);
			}
		}

		Car._initialized=true;
	}