Inheritance in Swift

class Puppy: Dog {
    override init(name: String) { super.init(name: name) }
    func whine() { print("whimper") }
}

Full lesson:

Inheritance is one of the four classic OOP pillars (along with encapsulation, polymorphism, and abstraction). The idea is simple: most real-world things are kinds of other things — a Puppy is a Dog, a Car is a Vehicle, a Manager is an Employee. When you model that "is-a" relationship in code, the child class gets the parent's data and behavior automatically.

What gets inherited?

• Fields — the Puppy has a name field even though we only declared it on Dog.
• Methods — the Puppy can call bark() even though we only defined it on Dog.
• The contract — anywhere code expects a Dog, you can pass a Puppy (we'll see this when we cover polymorphism).

What you still write

• An initializer that forwards arguments up to the parent's initializer with super.init (because the parent's fields need initializing). If a subclass adds no stored properties and declares no initializer, it inherits the parent's; here you write one with override init to see super.init in action.
• Any new methods or new fields specific to the child.

Your task

Below the Dog class, create a Puppy class that inherits from Dog and adds one new method, whine(), that prints "whimper". The harness creates a Puppy named "Buddy", calls its inherited bark(), and then its new whine().

Expected output:

Woof! I am Buddy
whimper