//最常用的继承模式

    function SuperType(name){

        this.name = name;

        this.color = ["yellow","green"];

    }

    SuperType.prototype.getName = function(){

        return this.name;

    };

    function SubType (name,age){

        SuperType.call(this,name);

    }

    SubType.prototype = new SubType();

    SubType.prototype.constructor = SubType;

    SubType.prototype.getAge = function (){

        return this.age;

    };

    var instance = new SubType("xiaodong",22);

    instance.color.push("black");

    var instance2 = new SubType("tiantian",11);

    console.log(instance.color);// ["yellow", "green", "black"]

    console.log(instance2.color);// ["yellow", "green"]

    console.log(instance.getName == instance2.getName);//true 实现了方法共享

    console.log(instance.getAge == instance2.getAge);//true 实现了方法共享