菜鸟教程在线编辑器

AI 编程工具
 
                <!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(runoob.com)</title>
</head>
<body>

<h2>JavaScript 类继承</h2>

<p>JavaScript 类继承使用 extends 关键字。</p>
<p>"super" 方法用于调用父类的构造函数。</p>

<p id="demo"></p>

<script>
class Site {
  constructor(name) {
    this.sitename = name;
  }
  present() {
    return '我喜欢' + this.sitename;
  }
}
 
class Runoob extends Site {
  constructor(name, age) {
    super(name);
    this.age = age;
  }
  show() {
    return this.present() + ', 它创建了 ' + this.age + ' 年。';
  }
}
 
let noob = new Runoob("菜鸟教程", 5);
document.getElementById("demo").innerHTML = noob.show();
</script>

</body>
</html>
              