1.使用call和apply完成属性的继承

2用原型链的方法实现方法的继承

     function Person(name, age) {
            this.name = name;
            this.age = age;
        }

        //方法
        Person.prototype.say = function() {
            console.log(this.name + " 在哈哈大笑");
        }


      
        function Student(no, name, age) {
            this.no = no;
            // Person.call(this, name, age); //对象冒充
            Person.apply(this, [name, age]);
        }


        //将父类的对象实例(new Person())赋值给子类的原型对象( Student.prototype)
        // Student.prototype = new Person();//原型链继承
        Student.prototype = new Person();

        Student.prototype.study = function() {
            console.log(this.name + " 打瞌睡");
        }

        var s = new Student(1000, '小刚', 6);
        console.log(s);
        s.say()