类和继承

类

class Person {
    constructor(name, age) {
        this.name = name;
        this.age = age;
    }

    sayHello() {
        console.log(`Hello, my name is ${this.name} and I am ${this.age} years old.`);
    }
}

const person1 = new Person('John', 25);
person1.sayHello(); // 输出 "Hello, my name is John and I am 25 years old."

继承

class Student extends Person {
    constructor(name, age, major) {
        super(name, age);
        this.major = major;
    }

    sayHello() {
        console.log(`Hello, my name is ${this.name} and I am a ${this.major} student.`);
    }
}

const student1 = new Student('Jane', 20, 'Computer Science');
student1.sayHello(); // 输出 "Hello, my name is Jane and I am a Computer Science student."