JavaScript-ES6继承

ES6 之前的继承

在子类中通过 call/apply 方法然后在借助父类的构造函数
将子类的原型对象设置为父类的实例对象

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>ES6继承</title>
    <script>
        function Person(name, age) {
            this.name = name;
            this.age = age;
        }

        Person.prototype.say = function () {
            console.log(this.name, this.age);
        }

        function Student(name, age, score) {
            // 1.在子类中通过call/apply方法借助父类的构造函数
            Person.call(this, name, age);
            this.score = score;
            this.study = function () {
                console.log("day day up");
            }
        }

        // 2.将子类的原型对象设置为父类的实例对象
        Student.prototype = new Person();
        Student.prototype.constructor = Student;

        let stu = new Student("BNTang", 18, 99);
        stu.say();
    </script>
</head>
<body>
</body>
</html>

在 ES6 中如何继承，在子类后面添加 extends 并指定父类的名称，在子类的 constructor 构造函数中通过 super 方法借助父类的构造函数

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>ES6继承</title>
    <script>
        // ES6开始的继承
        class Person {
            constructor(name, age) {
                this.name = name;
                this.age = age;
            }

            say() {
                console.log(this.name, this.age);
            }
        }

        // 以下代码的含义: 告诉浏览器将来Student这个类需要继承于Person这个类
        class Student extends Person {
            constructor(name, age, score) {
                super(name, age);
                this.score = score;
            }

            study() {
                console.log("day day up");
            }
        }

        let stu = new Student("zs", 18, 98);
        stu.say();
    </script>
</head>
<body>
</body>
</html>