1 // JavaScript Document
2 //创建三个构造函数
3 function Shape(){
4 this.name='ahape';
5 this.toString=function(){return this.name;}
6 }
7
8 function TwoDShape(){
9 this.name=''2D shape;
10 }
11 function Triangle(side,height){
12 this.name='Triangel';
13 this.side=side;
14 this.height=height;
15 this.getArea=function(){return this.side * this.height/2;}
16 }
17
18 //实现继承
19 TwoDShape.prototype=new Shape();
20 Triangle.prototype=new TwoDShape();
21 //实现继承关系后，重置原型的构造器属性
22 TwoDShape.prototype.constructor=TwoDShape;
23 Triangle.prototype.constructor=Triangle;
24 //创建一个Triangle对象，并调用getArea方法
25 var my=new Triangle(5,10);
26 my.getArea();
