enum Suit: String {
    case spades = "♠"
    case hearts = "♥"
    case diamonds = "♦"
    case clubs = "♣"
}

例如,我怎么做这样的事情:

for suit in Suit {
    // do something with suit
    print(suit.rawValue)
}

结果示例:

♠
♥
♦
♣

当前回答

这是一个相当老的帖子,来自Swift 2.0。现在有一些更好的解决方案,使用了swift 3.0的新特性: 在Swift 3.0中迭代一个Enum

关于这个问题,有一个解决方案,它使用了Swift 4.2的一个新功能(在我写这篇编辑时还没有发布): 我如何得到一个Swift枚举的计数?


在这个帖子中有很多好的解决方案,但其中一些非常复杂。我喜欢尽可能地简化。这里有一个解决方案,可能适用于不同的需求,但我认为它在大多数情况下都很好:

enum Number: String {
    case One
    case Two
    case Three
    case Four
    case EndIndex

    func nextCase () -> Number
    {
        switch self {
        case .One:
            return .Two
        case .Two:
            return .Three
        case .Three:
            return .Four
        case .Four:
            return .EndIndex

        /* 
        Add all additional cases above
        */
        case .EndIndex:
            return .EndIndex
        }
    }

    static var allValues: [String] {
        var array: [String] = Array()
        var number = Number.One

        while number != Number.EndIndex {
            array.append(number.rawValue)
            number = number.nextCase()
        }
        return array
    }
}

迭代:

for item in Number.allValues {
    print("number is: \(item)")
}

其他回答

这篇文章是相关的https://www.swift-studies.com/blog/2014/6/10/enumerating-enums-in-swift

基本上,提议的解决方案是

enum ProductCategory : String {
     case Washers = "washers", Dryers = "dryers", Toasters = "toasters"

     static let allValues = [Washers, Dryers, Toasters]
}

for category in ProductCategory.allValues{
     //Do something
}

你可以试着像这样列举

enum Planet: String {
    case Mercury
    case Venus
    case Earth
    case Mars

    static var enumerate: [Planet] {
        var a: [Planet] = []
        switch Planet.Mercury {
            case .Mercury: a.append(.Mercury); fallthrough
            case .Venus: a.append(.Venus); fallthrough
            case .Earth: a.append(.Earth); fallthrough
            case .Mars: a.append(.Mars)
        }
    return a
    }
}

Planet.enumerate // [Mercury, Venus, Earth, Mars]

Xcode 10与Swift 4.2

enum Filter: String, CaseIterable {

    case salary = "Salary"
    case experience = "Experience"
    case technology = "Technology"
    case unutilized = "Unutilized"
    case unutilizedHV = "Unutilized High Value"

    static let allValues = Filter.allCases.map { $0.rawValue }
}

叫它

print(Filter.allValues)

打印:

[“薪酬”、“经验”、“技术”、“未利用”、“未利用的高价值”]


旧版本

对于表示Int的enum

enum Filter: Int {
    case salary
    case experience
    case technology
    case unutilized
    case unutilizedHV
    
    static let allRawValues = salary.rawValue...unutilizedHV.rawValue  // First to last case
    static let allValues = allRawValues.map { Filter(rawValue: $0)!.rawValue }
}

这样叫它:

print(Filter.allValues)

打印:

[0, 1, 2, 3, 4]


用于表示字符串的enum

enum Filter: Int {
    case salary
    case experience
    case technology
    case unutilized
    case unutilizedHV
    
    static let allRawValues = salary.rawValue...unutilizedHV.rawValue  // First to last case
    static let allValues = allRawValues.map { Filter(rawValue: $0)!.description }
}

extension Filter: CustomStringConvertible {
    var description: String {
        switch self {
        case .salary: return "Salary"
        case .experience: return "Experience"
        case .technology: return "Technology"
        case .unutilized: return "Unutilized"
        case .unutilizedHV: return "Unutilized High Value"
        }
    }
}

叫它

print(Filter.allValues)

打印:

[“薪酬”、“经验”、“技术”、“未利用”、“未利用的高价值”]

在处理Swift 2.0时,以下是我的建议:

我已经将原始类型添加到Suit enum

enum Suit: Int {

然后:

struct Card {
    var rank: Rank
    var suit: Suit


    func fullDeck()-> [Card] {

        var deck = [Card]()

        for i in Rank.Ace.rawValue...Rank.King.rawValue {

            for j in Suit.Spades.rawValue...Suit.Clubs.rawValue {

                deck.append(Card(rank:Rank(rawValue: i)! , suit: Suit(rawValue: j)!))
            }
        }

        return deck
    }
}

有时,您可能会处理具有底层原始整数类型的枚举类型,这种类型在整个软件开发生命周期中都会发生变化。下面是一个很适合这种情况的例子:

public class MyClassThatLoadsTexturesEtc
{
    //...

    // Colors used for gems and sectors.
    public enum Color: Int
    {
        // Colors arranged in order of the spectrum.
        case First = 0
        case Red, Orange, Yellow, Green, Blue, Purple, Pink
        // --> Add more colors here, between the first and last markers.
        case Last
    }

    //...

    public func preloadGems()
    {
        // Preload all gems.
        for i in (Color.First.toRaw() + 1) ..< (Color.Last.toRaw())
        {
            let color = Color.fromRaw(i)!
            loadColoredTextures(forKey: color)
        }
    }

    //...
}