父类衍生子类 

 1 function Person(name, age){
 2     this.name = name
 3     this.age = age
 4 }
 5 Person.prototype.say = (name) => {
 6     console.log('person', name)
 7 }
 8 function Student(sex){
 9     Person.apply(this, arguments)
10     this.sex = sex
11 }
12 Student.prototype.say = (name) => {
13     console.log('student', name)
14 }
15 // Student.prototype = Person.prototype
16 // Student.prototype.constructor = Student
17 let F= function(){}
18 F.prototype = Person.prototype
19 Student.prototype = new F()
20 Student.prototype.constructor = Student
21 
22 let tom = new  Student('tom', 20, '男')
23 tom.say('hello') //person:hello

方法缺点：

调用了父类的方法，子类没有重写

 

方法二：

 1 // 父类方法重写
 2 var parent = function(name, age) {
 3     this.name = name;
 4     this.age = age
 5 }
 6 parent.prototype.showProper = function(){
 7     console.log('name:' + this.name + ';age:' + this.age)
 8 }
 9 // var child = new parent()
10 var child = function(name,age){
11     parent.call(this,name,age);
12 }
13 child.prototype = Object.create(parent.prototype);
14 child.prototype.constructor = child
15 child.prototype.showProper = function() {
16     console.log('子元素' + this.name)
17 }
18 var obj = new child('test','2')
19 obj.showProper()

有时间还是再看一下原型链吧

posted on 2018-04-25 11:35  Newbies  阅读(116)  评论(0)    收藏  举报

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