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:
♠
♥
♦
♣
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
我添加了函数count(),并迭代值:
public enum MetricType: Int {
case mvps = 0
case allNBA = 1
case championshipRings = 2
case finalAppearances = 3
case gamesPlayed = 4
case ppg = 5
static func count() -> Int {
return (ppg.rawValue) + 1
}
static var allValues: [MetricType] {
var array: [MetricType] = Array()
var item : MetricType = MetricType.mvps
while item.rawValue < MetricType.count() {
array.append(item)
item = MetricType(rawValue: (item.rawValue + 1))!
}
return array
}
}
其他回答
如果您仍然想为Rank和Suit使用枚举,这里有一个不那么神秘的例子。如果您想使用for-in循环遍历每个对象,只需将它们收集到一个Array中。
标准52张牌的例子:
enum Rank: Int {
case Ace = 1, Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King
func name() -> String {
switch self {
case .Ace:
return "ace"
case .Jack:
return "jack"
case .Queen:
return "queen"
case .King:
return "king"
default:
return String(self.toRaw())
}
}
}
enum Suit: Int {
case Diamonds = 1, Clubs, Hearts, Spades
func name() -> String {
switch self {
case .Diamonds:
return "diamonds"
case .Clubs:
return "clubs"
case .Hearts:
return "hearts"
case .Spades:
return "spades"
default:
return "NOT A VALID SUIT"
}
}
}
let Ranks = [
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 Suits = [
Suit.Diamonds,
Suit.Clubs,
Suit.Hearts,
Suit.Spades
]
class Card {
var rank: Rank
var suit: Suit
init(rank: Rank, suit: Suit) {
self.rank = rank
self.suit = suit
}
}
class Deck {
var cards = Card[]()
init() {
for rank in Ranks {
for suit in Suits {
cards.append(Card(rank: rank, suit: suit))
}
}
}
}
var myDeck = Deck()
myDeck.cards.count // => 52
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)
}
}
//...
}
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)")
}
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
}
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”]