Swift 如何遍历enum

情景

有这么一个枚举类型

enum Animals:String {
    case Frog = “Frog”
    case Cat = “Cat”
    case Dog = “Dog”
    case Lion = “Lion”
    case Tiger = “Tiger”
    case Cattle = “Cattle”
}

现在我们需要把 Animals 的每个值都打印出来。
如果我们像遍历数组那么做

for animal in Animals {
    print(animal.rawValue)
}

将得到错误提示

Type ‘Animals.Type’ does not conform to protocol ‘SequenceType’

解决方法

让我们来点小技巧化解这个尴尬的局面

enum Animals:String {
    case Frog = “Frog”
    case Cat = “Cat”
    case Dog = “Dog”
    case Lion = “Lion”
    case Tiger = “Tiger”
    case Cattle = “Cattle”
    static let allValues = [Frog,Cat,Dog,Lion,Tiger,Cattle]
}    

可能你已经猜到接下来该做些什么了

for animal in Animals.allValues {
    print(animal.rawValue)
}