struct BlackjackCard {
    
    // struct 안에서 enum 정의
    enum Suit: Character {
        case spades = "♠", hearts = "♡", diamonds = "♢", clubs = "♣"
    }

    // struct 안에서 enum 정의
    enum Rank: Int {
        case two = 2, three, four, five, six, seven, eight, nine, ten
        case jack, queen, king, ace
        
        // enum 안에서 struct 정의
        struct Values {
            let first: Int, second: Int?
        }
        var values: Values {
            switch self {
                case .ace:
                    return Values(first: 1, second: 11)
                case .jack, .queen, .king:
                    return Values(first: 10, second: nil)
                default:
                    return Values(first: self.rawValue, second: nil)
            }
        }
    }

    let rank: Rank, suit: Suit
    var description: String {
        var output = "suit is \(suit.rawValue),"
        output += " value is \(rank.values.first)"
        if let second = rank.values.second {
            output += " or \(second)"
        }
        return output
    }
 }

let heartsSymbol = BlackjackCard.Suit.hearts.rawValue
// heartsSymbol is "♡"