js继承

参数版-----------------------------------------------

function Rect(width, height){

    this.width = width;

    this.height = height;

    this.area = function(){return this.width*this.height;};

}

function myRect(width, height, name){

    Rect.call(this,width,height);

    this.name = name;

    this.show = function(){

    alert(this.name+” with area:”+this.area());

    }

}

对象版---------------------------------------

        function Rect(config){

                this.width = config.width;

                this.height = config.height;

                this.area = function(){return this.width*this.height;};

        }

        function myRect(config){

                Rect.call(this,config);

                this.name = config.name;

                this.show = function(){

                alert(this.name+" with area:"+this.area());

                }

        }

        var a =new myRect({width:1,heigth:2,name:3});

        var b =a.width;

        alert(b);