下面是我用来迭代枚举和从一个枚举提供多个值类型的方法

enum IterateEnum: Int {
    case Zero
    case One
    case Two
    case Three
    case Four
    case Five
    case Six
    case Seven

    //tuple allows multiple values to be derived from the enum case, and
    //since it is using a switch with no default, if a new case is added,
    //a compiler error will be returned if it doesn't have a value tuple set
    var value: (french: String, spanish: String, japanese: String) {
        switch self {
        case .Zero: return (french: "zéro", spanish: "cero", japanese: "nuru")
        case .One: return (french: "un", spanish: "uno", japanese: "ichi")
        case .Two: return (french: "deux", spanish: "dos", japanese: "ni")
        case .Three: return (french: "trois", spanish: "tres", japanese: "san")
        case .Four: return (french: "quatre", spanish: "cuatro", japanese: "shi")
        case .Five: return (french: "cinq", spanish: "cinco", japanese: "go")
        case .Six: return (french: "six", spanish: "seis", japanese: "roku")
        case .Seven: return (french: "sept", spanish: "siete", japanese: "shichi")
        }
    }

    //Used to iterate enum or otherwise access enum case by index order.
    //Iterate by looping until it returns nil
    static func item(index: Int) -> IterateEnum? {
        return IterateEnum.init(rawValue: index)
    }

    static func numberFromSpanish(number: String) -> IterateEnum? {
        return findItem { $0.value.spanish == number }
    }

    //use block to test value property to retrieve the enum case        
    static func findItem(predicate: ((_: IterateEnum) -> Bool)) -> IterateEnum? {

        var enumIndex: Int = -1
        var enumCase: IterateEnum?

        //Iterate until item returns nil
        repeat {
            enumIndex += 1
            enumCase = IterateEnum.item(index: enumIndex)

            if let eCase = enumCase {

                if predicate(eCase) {
                    return eCase
                }
            }
        } while enumCase != nil
        return nil
    }
}

var enumIndex: Int = -1
var enumCase: IterateEnum?

// Iterate until item returns nil
repeat {
    enumIndex += 1
    enumCase = IterateEnum.item(index: enumIndex)
    if let eCase = enumCase {
        print("The number \(eCase) in french: \(eCase.value.french), spanish: \(eCase.value.spanish), japanese: \(eCase.value.japanese)")
    }
} while enumCase != nil

print("Total of \(enumIndex) cases")

let number = IterateEnum.numberFromSpanish(number: "siete")

print("siete in japanese: \((number?.value.japanese ?? "Unknown"))")

输出如下:

法语中的数字Zero: zéro，西班牙语中的数字cero，日语中的数字nuru 数字一在法语中是un，西班牙语中是uno，日语中是ichi 法语中的数字2是deux，西班牙语中的数字2是dos，日语中的数字2是ni 法语中的“三”是“trois”，西班牙语中的“tres”，日语中的“san” 法语中的“四”是quatre，西班牙语中的“四”是cuatro，日语中的“四”是shi 数字五在法语中是cinq，西班牙语中是cinco，日语中是go 数字6在法语中是Six，西班牙语是seis，日语是roku 法语中的数字“七”是“sept”，西班牙语中的“siete”，日语中的“shichi”

共8例

Siete在日语中的意思是:shichi

更新

我最近创建了一个协议来处理枚举。该协议需要一个Int原始值的enum:

protocol EnumIteration {

    //Used to iterate enum or otherwise access enum case by index order. Iterate by looping until it returns nil

    static func item(index:Int) -> Self?
    static func iterate(item:((index:Int, enumCase:Self)->()), completion:(()->())?) {
    static func findItem(predicate:((enumCase:Self)->Bool)) -> Self?
    static func count() -> Int
}

extension EnumIteration where Self: RawRepresentable, Self.RawValue == Int {

    //Used to iterate enum or otherwise access enum case by index order. Iterate by looping until it returns nil
    static func item(index:Int) -> Self? {
        return Self.init(rawValue: index)
    }

    static func iterate(item:((index:Int, enumCase:Self)->()), completion:(()->())?) {

        var enumIndex:Int = -1
        var enumCase:Self?

        //Iterate until item returns nil
        repeat {
            enumIndex += 1
            enumCase = Self.item(enumIndex)

            if let eCase = enumCase {
                item(index: enumIndex, enumCase: eCase)
            }
        } while enumCase != nil
        completion?()
    }

    static func findItem(predicate:((enumCase:Self)->Bool)) -> Self? {

        var enumIndex:Int = -1
        var enumCase:Self?

        //Iterate until item returns nil
        repeat {
            enumIndex += 1
            enumCase = Self.item(enumIndex)

            if let eCase = enumCase {

                if predicate(enumCase:eCase) {
                    return eCase
                }
            }
        } while enumCase != nil
        return nil
    }

    static func count() -> Int {
        var enumIndex:Int = -1
        var enumCase:Self?

        //Iterate until item returns nil
        repeat {
            enumIndex += 1
            enumCase = Self.item(enumIndex)
        } while enumCase != nil

        //last enumIndex (when enumCase == nil) is equal to the enum count
        return enumIndex
    }
}

这个问题现在简单多了。以下是我的Swift 4.2解决方案:

enum Suit: Int, CaseIterable {
  case None
  case Spade, Heart, Diamond, Club

  static let allNonNullCases = Suit.allCases[Spade.rawValue...]
}

enum Rank: Int, CaseIterable {
  case Joker
  case Two, Three, Four, Five, Six, Seven, Eight
  case Nine, Ten, Jack, Queen, King, Ace

  static let allNonNullCases = Rank.allCases[Two.rawValue...]
}

func makeDeck(withJoker: Bool = false) -> [Card] {
  var deck = [Card]()
  for suit in Suit.allNonNullCases {
    for rank in Rank.allNonNullCases {
      deck.append(Card(suit: suit, rank: rank))
    }
  }
  if withJoker {
    deck.append(Card(suit: .None, rank: .Joker))
  }
  return deck
}

4。2:

我喜欢这个解决方案，我把找到“列表理解在Swift”。

它使用Int rawws而不是string，但它避免了键入两次，它允许自定义范围，并且不硬编码原始值。

这是我最初解决方案的Swift 4版本，但请参阅上面的4.2改进:

enum Suit: Int {
  case None
  case Spade, Heart, Diamond, Club

  static let allRawValues = Suit.Spade.rawValue...Suit.Club.rawValue
  static let allCases = Array(allRawValues.map{ Suit(rawValue: $0)! })
}
enum Rank: Int {
  case Joker
  case Two, Three, Four, Five, Six
  case Seven, Eight, Nine, Ten
  case Jack, Queen, King, Ace

  static let allRawValues = Rank.Two.rawValue...Rank.Ace.rawValue
  static let allCases = Array(allRawValues.map{ Rank(rawValue: $0)! })
}
func makeDeck(withJoker: Bool = false) -> [Card] {
  var deck = [Card]()
  for suit in Suit.allCases {
    for rank in Rank.allCases {
      deck.append(Card(suit: suit, rank: rank))
    }
  }
  if withJoker {
    deck.append(Card(suit: .None, rank: .Joker))
  }
  return deck
}

我的解决方案是声明一个包含所有枚举可能性的数组。所以for循环可以遍历所有这些。

//Function inside struct Card
static func generateFullDeck() -> [Card] {
    let allRanks = [Rank.Ace, Rank.Two, Rank.Three, Rank.Four, Rank.Five, Rank.Six, Rank.Seven, Rank.Eight, Rank.Nine, Rank.Ten, Rank.Jack, Rank.Queen, Rank.King]
    let allSuits = [Suit.Hearts, Suit.Diamonds, Suit.Clubs, Suit.Spades]
    var myFullDeck: [Card] = []

    for myRank in allRanks {
        for mySuit in allSuits {
            myFullDeck.append(Card(rank: myRank, suit: mySuit))
        }
    }
    return myFullDeck
}

//actual use:
let aFullDeck = Card.generateFullDeck()    //Generate the desired full deck

var allDesc: [String] = []
for aCard in aFullDeck {
    println(aCard.simpleDescription())    //You'll see all the results in playground
}

在Swift中，枚举类型可以像EnumType一样访问。案例:

let tableView = UITableView(frame: self.view. view)UITableViewStyle.Plain)

大多数情况下，只有当您有几个选项可以使用，并且确切地知道在每个选项上要做什么时，才会使用枚举类型。

在处理枚举类型时，使用for-in结构没有太大意义。

你可以这样做，例如:

func sumNumbers(numbers : Int...) -> Int {
    var sum = 0

    for number in numbers{
        sum += number
    }

    return sum
}

枚举有toRaw()和fromRaw()方法。所以如果你的原始值是Int，你可以从第一个枚举迭代到最后一个枚举:

enum Suit: Int {
    case Spades = 1
    case Hearts, Diamonds, Clubs
    func simpleDescription() -> String {
        switch self {
        case .Spades:
            return "spades"
        case .Hearts:
            return "hearts"
        case .Diamonds:
            return "diamonds"
        case .Clubs:
            return "clubs"
        }
    }
}

for i in Suit.Spades.toRaw()...Suit.Clubs.toRaw() {
    if let covertedSuit = Suit.fromRaw(i) {
        let description = covertedSuit.simpleDescription()
    }
}

一个问题是在运行simpleDescription方法之前需要测试可选值，因此我们首先将convertedSuit设置为我们的值，然后将常量设置为convertedSuit.simpleDescription()

原则上，如果你不为enum的大小写使用原始值赋值，这样做是可能的:

enum RankEnum: Int {
  case Ace
  case One
  case Two
}

class RankEnumGenerator: Generator {
    var i = 0
    typealias Element = RankEnum
    func next() -> Element? {
        let r = RankEnum.fromRaw(i)
        i += 1
        return r
    }
}

extension RankEnum {
    static func enumerate() -> SequenceOf<RankEnum> {
        return SequenceOf<RankEnum>({ RankEnumGenerator() })
    }
}

for r in RankEnum.enumerate() {
    println("\(r.toRaw())")
}