javascript怎么编写继承 怎么在网页上面显示

Question

 

Answer 1

class A {
    constructor(name) {
        this.name = name;
    }
    sayHello() {
        return this.name + " say Hello!";
    }
}

class B extends A {
    constructor(name, id) {
        super(name);
        this.id = id;
    }
    checkId(ID) {
        return this.id === ID;
    }
}

// 创建实例
let instanceB = new B("John", 123);

// 在网页上显示继承结果
document.write(instanceB.sayHello() + "<br>");
document.write("Check ID result: " + instanceB.checkId(123) + "<br>");