2-6 继承

1-1 call实现属性继承

            function Person(name,age){
            this.name = name;
            this.age = age;
        }
        function Teacher(name,age,skill){
            var self = this;
            Person.call(self,name,age)
            this.skill = skill;
        }
        var t = new Teacher("zhang",18,"js");
        console.log(t)

             function Person(name,age){
            this.name = name;
            this.age = age;
        }
        function Teacher(name,age,skill){
            Person.call(this,name,age)
            this.skill = skill;
        }
        var t = new Teacher("zhang",18,"js");
        console.log(t)

1-2 方法的继承

                function Person(name,age){
            this.name = name;
            this.age = age;
        }
        Person.prototype.sayName = function(){
            console.log(this.name)
        }
        function Student(name,age,skill){
            Person.call(this,name,age);
            this.skill=skill;
        }
        Student.prototype = new Person();
                Student.prototype.constructor = Student;
        var s = new Student("cheng",18,"js");
        console.log(s.constructor == Student)

                function Person(name,age){
            this.name = name;
            this.age = age;
        }
        Person.prototype.sayName = function(){
            console.log(this.name)
        }
        function Student(name,age,skill){
            Person.call(this,name,age);
            this.skill=skill;
        }
        Student.prototype = Person.prototype;
                Student.prototype.constructor = Student;
                Student.prototype.sayAge = function(){
              console.log(this.age)
        }
        var s = new Student("cheng",18,"js");
        console.log(s.constructor == Student)

1-3 Object.create实现继承

如果想创建一个继承自其他对象的对象,可以使用Object.create()指定[[Prototype]]为一个新的对象。

                function Person(){
        }
        Person.prototype.sayName = function(){
            console.log("name")
        }
        function Teacher(){
        }
        Teacher.prototype =  Object.create(Person.prototype,{
            constructor:{
                value:Teacher
            }
        });
        var t = new Teacher();
        var p = new Person();
        console.log(t);