Error creating an instance
importance: 5
Here’s the code with Rabbit
extending Animal
.
Unfortunately, Rabbit
objects can’t be created. What’s wrong? Fix it.
class Animal {
constructor(name) {
this.name = name;
}
}
class Rabbit extends Animal {
constructor(name) {
this.name = name;
this.created = Date.now();
}
}
let rabbit = new Rabbit("White Rabbit"); // Error: this is not defined
alert(rabbit.name);
That’s because the child constructor must call super()
.
Here’s the corrected code:
class Animal {
constructor(name) {
this.name = name;
}
}
class Rabbit extends Animal {
constructor(name) {
super(name);
this.created = Date.now();
}
}
let rabbit = new Rabbit("White Rabbit"); // ok now
alert(rabbit.name); // White Rabbit