题目1

       function Teacher() {
            this.student = 500;
            this.skill = ["JS", "JQ"];
        }
        var teacher = new Teacher();
        Student.prototype = teacher;
        function Student() { }
        var student = new Student();
        student.student++;
        student.skill.push("HTML", "CSS");
        console.log(student);
        console.log(teacher);

自类不能修改父类的值

综合题目

原型与this

          function Parent() {
            this.a = 1;
            this.b = [1, 2, this.a];
            this.c = { demo: 5 };
            this.show = function () {
                console.log(this.a, this.b, this.c.demo);
            }
        }
        function Child() {
            this.a = 2;
            this.change = function () {
                this.b.push(this.a);
                this.a = this.b.length;
                this.c.demo = this.a++;
            }
        }
        Child.prototype = new Parent();
        var parent = new Parent();//1 [1,2,1],5
        var child1 = new Child();//11  1,[1,2,1],5
        var child2 = new Child();//12 1,[1,2,1],5
        child1.a = 11;
        child2.a = 12;
        parent.show();//1 [1,2,1],5
        // 通过new Parent执行，
        child1.show();//11,[1,2,1],5
        child2.show();//12,[1,2,1],5
        child1.change();//5,[1,2,1,11],4
        child2.change();//6,[1,2,1,11,12],5
        parent.show();//1,[1,2,1],5
        child1.show();//5,[1,2,1,11,12],5
        child2.show();//6,[1,2,1,11,12],5

原型

全是true

instanceof会遍历原型链

全是true