Android(override val version: String = "14"): Platform { override fun greet() { println("Hello, Android $version”) } } val platform = Android() protocol Platform { var version: String { get } func greet() } class Ios : Platform { let version: String init(version: String = "17") { self.version = version } func greet() { print("Hello, iOS \(version)") } } let platform = Ios() Classes