class Animal {
constructor(name) {
console.log('name: ', name); // lucy
this.name = name;
}
sayHi() {
return `My name is ${this.name}`;
}
}
let a = new Animal('lucy');
console.log(a.sayHi()); // My name is lucy
class Child extends Animal {
constructor(name) {
super(name); // 调用父类的 constructor(name)
}
sayHi() {
return 'Alice, ' + super.sayHi(); // 调用父类的 sayHi()
}
}
let c = new Child('Tom');
console.log(c.sayHi()); Alice, My name is Tom
