JavaScript的面向对象编程

JavaScript的面向对象编程

1 .__proto__关键字(找个原型对象)

用关键字，给对象找个父类，这个父类叫原型对象。然后对象就有了原型对象的属性和方法。

而且可以在代码种，改变原型对象。

完整代码如下：

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>JavaScript学习</title>
<script>
'use strict';
var Student = {
name: "WangZan",
age: 25,
run: function () {
console.log(this.name + " run...");
}
};

var xiaoming = {
name: "xiaoming"
};

xiaoming.__proto__ = Student;
console.log(xiaoming.run());

var Bird = {

fly: function () {
console.log(this.name + " fly...");
}
};

xiaoming.__proto__ = Bird;
console.log(xiaoming.fly());

</script>
</head>
<body>
</body>
</html>

2 class继承（推荐用这个，比上面的原型继承要好）

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>JavaScript学习</title>
    <script>
        'use strict';
        class Student{
           constructor(name) {
               this.name = name;
           }
            hello () {
                alert(this.name);
            }
        }
​
        class xiaoStudent extends Student {
            constructor(name,grade) {
                super(name);
                this.grade = grade;
            }
            hello_2 () {
                alert(this.name + this.grade);
            }
        }
​
        var xiaoming = new Student("xiaoming");
        xiaoming.hello();    //输出：xiaoming
        var xiaoming = new xiaoStudent("WangZan",1);
        xiaoming.hello_2();  //输出：WangZan1
​
    </script>
</head>
<body>
</body>
</html>

 

posted @ 2020-02-20 22:32  WZ_BeiHang  阅读(705)  评论(0)    收藏  举报