编辑代码

enum Suit {
    case Spades, Hearts, Diamonds,  Clubs
    func simpleDescription() -> String {
        switch self {
            case .Spades:
               return "spades"
            case .Hearts:
               return "hearts"
            case .Diamonds:
               return "diamonds"
            case .Clubs:
               return "clubs"
        }
    }
}
let hearts = Suit.Hearts
let heartsDescription = hearts.simpleDescription()

let hearts = Suit.Hearts
let heartsDescription = hearts.simpleDescription()
struct Card {
    var rank: Rank
    var suit: Suit
    func simpleDescription() -> String {
        return "The \(rank.simpleDescription()) of \(suit.simpleDescription())"
    }
}
let threeOfSpades = Card(rank: .Three, suit: .Spades)
let threeOfSpadesDescription = threeOfSpades.simpleDescription()

 enum ServerResponse {
    case Result(String, String)
    case Failure(String)
}

let success = ServerResponse.Result("6:00 am", "8:09 pm")
let failure = ServerResponse.Failure("Out of cheese.")

switch success {
case let .Result(sunrise, sunset):
    let ServerResponse = "Sunrise is at \(sunrise) and sunset is at \(sunset)."
    case let .Failure(message):
    print("Failure... \(message)")
}