/*
                继承：
                    儿子继承爸爸；
                    儿子可以用爸爸的方法和属性；
                    儿子的改变不影响爸爸；
            */
            
            // 构造函数 == 类
        function Person( name , age , marry , sex ){
                this.name = name;
                this.age = age;
                this.marry = marry;
                this.sex = sex;
            };

        Person.prototype.showName = function(){
                console.log( this.name+'is walking' );
            };
            Person.prototype.yy = function(){
                console.log( this.name+'is YY' );
            };


            // 通过继承创造一个子类
        function PersonChild(  pArr , weight ){
                Person.apply( this , pArr );
                this.weight = weight;
            };
            
        //PersonChild.prototype = Person.prototype;
         PersonChild.prototype = Object.create(Person.prototype)
        PersonChild.prototype.showAge = function(){
                alert( this.age );
            };


        var oP = new PersonChild( ['青青' , '18' , false , 1] , 60 );

                oP.showName()
                oP.yy()
                oP.showAge()