1 ??
struct BlackjackCard { // 二十一點
// nested Suit enumeration
enum Suit: Character { // 描述撲克牌的四種花色
case spades = "?", hearts = "?", diamonds = "?", clubs = "?"
}
// nested Rank enumeration
enum Rank: Int {
case two = 2, three, four, five, six, seven, eight, nine, ten
case jack, queen, king, ace
struct Values { // 用來反映Ace的兩個數(shù)值()
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)
}
}
}
// BlackjackCard properties and methods
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)")
2 引用嵌套類型
let heartsSymbol = BlackjackCard.Suit.hearts.rawValue
playground文件在andyRon/LearnSwift
