嵌套

import UIKit

struct BlackjackCard {
    
    // 嵌套Suit 枚舉
    enum Suit: Character {
        case spades = "?", hearts = "?", diamonds = "?", clubs = "??"
    }
    
    // 嵌套R(shí)ank 枚舉
    enum Rank: Int {
        case two = 2, three, four, five, six, seven, eight, nine
        case jack, queen, king, ace
        
        // 嵌套 Values 結(jié)構(gòu)體
        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 theAceOfSpades = BlackjackCard(rank: .ace, suit: .spades)
print("theAceOfSpades: \(theAceOfSpades.description)")


let heartsSymbol = BlackjackCard.Suit.hearts.rawValue
print(heartsSymbol)

console log 如下

嵌套類型.png