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>
