TL ; DR:
Inside a method of a class that extends another, super.bark() calls the parent's version of bark on the same object. This lets you extend the parent's behavior instead of replacing it.
class Puppy extends Dog {
bark() {
super.bark(); // do everything the parent did
console.log("Yip! Said " + this.name);
}
}
Why it matters
Overriding a method replaces the parent's behavior. Often you want to extend it instead: keep what the parent did and add something more. A typical example is a save method: the parent writes the row to the database, and a subclass runs the parent's save first and then writes a log line.
Your task
The Puppy class already overrides bark, but the body is empty. Inside Puppy's bark():
- call the parent's version with
super.bark();, soWoof! I am <name>still prints; - then
console.log("Yip! Said " + this.name);.
Notes:
super.bark()works inside a class method;superby itself refers to the parent class (Dog).this.namewas set byDog's constructor;Puppyhas no constructor of its own, so it inherits it.
The driver (already written, it runs when you press Run):
let buddy = new Puppy("Buddy");
buddy.bark();
let rex = new Puppy("Rex");
rex.bark();
let dog = new Dog("Max");
dog.bark();
buddyis aPuppy: itsbarkprints the parent's line, then its own.rexis anotherPuppy: the names come from the object, nothing is hard-coded.dogis a plainDog: itsbarkis unchanged and prints only the parent's line, with noYip!.
Expected output:
Woof! I am Buddy
Yip! Said Buddy
Woof! I am Rex
Yip! Said Rex
Woof! I am Max
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