final-protocol.swift

protocol Animal{
    var isIdle : Bool? {get set}
    func run()
    func stop()
}

protocol Eye{
    func closeEyesAndSleep()
    func openEyesAndLookAround()
}

class Cat : Eye{
    var isIdle: Bool? = true
    
    func closeEyesAndSleep() {
        if isIdle == true{
            print("Cat is sleeping now")
        }else{
            print("Cat will NOT sleeping now")
        }
    }
    
    func openEyesAndLookAround() {
        print("Cat is looking around")
    }
}

extension Cat : Animal{
    func run() {
        isIdle = true
        print("Cat is running now")
    }
    
    func stop() {
        isIdle = false
        print("Cat has stopped now")
    }
}


class Dog : Animal{
    var isIdle: Bool? = true
    
    func run() {
        print("Dog is running now")
    }
    
    func stop() {
        print("Dog has stopped now")
    }
}

let whiteCat = Cat()
let blackCat = Cat()
let pinkCat = Cat()

let blackDog = Dog()
let yellowDog = Dog()

var animalsArray : [Animal] = [whiteCat, blackCat, pinkCat, blackCat, yellowDog]