Dear team,

Requesting your constructive criticism of my solution to Checkpoint 7.

While I think I've got the classes right, what I'm unable to do, without seriously breaking the code, is to assign a default value to legs in the Animal class, and then have the option to give an instance of the final classes a different number of legs — should that be the case.

I learned in structs that you could assign a default value, and then choose to modify it when initialising. For example — "Pam Poovey giving herself 35 days of holiday when the default was about 14 days." How do I do that here with legs?

In the code below, though I've given the default value '4' to 'legs', if I remove the 'legs' parameter while initialising, I get wild errors and I can't fix it without two things breaking elsewhere. I tried; but I'm missing something.

Looking forward to your comments. Please also tell me if I've done something else wrong/inefficiently here:

import Cocoa

// Level #1
class Animal {
    var name: String
    var legs = 4

    init(name: String, legs: Int) {
        self.name = name
    }
}

// Level #2
class Dog: Animal {
    func speak() {
        print("Bark Bark.")
    }
}

class Cat: Animal {
    let isTame: Bool

    init(name: String, legs: Int, isTame: Bool) {
        self.isTame = isTame
        super.init(name: name, legs: legs)
    }

    func speak() {
        print("Meow Meow.")
    }
}

// Level #3
final class Corgi: Dog {
    override func speak() {
        print("Arf, Arf, Arf,... AAARrgf!!\", says \(name) the Corgi.")
    }
}

final class Poodle: Dog {
    override func speak() {
        print("Woooo! Woorf, Wooohrf!\", says \(name) the Poodle.")
    }
}

final class Persian: Cat {
    override func speak() {
        print("nnngrrreaou! nnnnreow! Mau.\", says \(name) the Persian Cat.")
    }
}

final class Lion: Cat {
    override func speak() {
        print("ROAAAAR! ROOOOOOOOOOARR!\", says \(name) the Lion.")
    }
}

// Creating & Testing Instances
let sandy = Corgi(name: "Sandy", legs: 3)
sandy.speak()
let hector = Poodle(name: "Hector", legs: 2)
hector.speak()

let scrapper = Persian(name: "Scrapper", legs: 4, isTame: false)
scrapper.speak()
let pumba = Lion(name: "Pumba", legs: 8, isTame: true)
pumba.speak()

I'm not entirely clear on what you are trying to do and what the problem you're running into is, but you can do something like this to have a default number of legs but also have the option to supply a different number if desired.

class Cat: Animal {
    let isTame: Bool

    init(name: String, legs: Int = 4, isTame: Bool) {
        self.isTame = isTame
        super.init(name: name, legs: legs)
    }

    func speak() {
        print("Meow Meow.")
    }
}

let scrapper = Persian(name: "Scrapper", isTame: false)
print(scrapper.legs) //4
let pumba = Lion(name: "Pumba", legs: 8, isTame: true)
print(pumba.legs) //8

Yeah, when I post the code that you have provided in a Playground it seems to work just fine. So, I'm not sure where the error is, but it may be in some other part of your code.