错误“无法读取未定义的属性“名称””

Question

我是学习 ES6 的新手，下面有以下代码。代码运行并执行正确的输出，但在我的控制台中我收到“无法读取未定义的属性‘名称’”。有人可以告诉我为什么会出现此错误。

class Vehicle {
    constructor(color = 'blue', wheels = 4, horn = 'beep beep') {
        this.color = color;
        this.wheels = wheels;
        this.horn = horn;
    }

    honkHorn() {
        console.log(this.horn);
    }
}

class Bicycle extends Vehicle{
    constructor(color, wheels, horn){
        super(color, wheels, horn);
        this.wheels = 2;
        this.horn = 'honk honk';
      
    }
 
}

const myVehicle = new Vehicle();
myVehicle.honkHorn(); // beep beep
const myBike = new Bicycle();
myBike.honkHorn(); // honk honk