浅谈javaScript中的继承关系<一>

 // JavaScript Document
 //创建三个构造函数
 function Shape(){
 this.name='ahape';
 this.toString=function(){return this.name;}
 }

 function TwoDShape(){
 this.name=''2D shape;
 }
 function Triangle(side,height){
 this.name='Triangel';
 this.side=side;
 this.height=height;
 this.getArea=function(){return this.side * this.height/2;}
 }    

 //实现继承
 TwoDShape.prototype=new Shape();
 Triangle.prototype=new TwoDShape();
 //实现继承关系后，重置原型的构造器属性
 TwoDShape.prototype.constructor=TwoDShape;
 Triangle.prototype.constructor=Triangle;
 //创建一个Triangle对象，并调用getArea方法
 var my=new Triangle(5,10);
 my.getArea();