如何将NSSet转换为[String]数组？

Question

我有一个NSSet of Strings，我想把它转换为[String]。我该怎么做？

Answer 1

我会使用map：

let nss = NSSet(array: ["a", "b", "a", "c"])

let arr = nss.map({ String($0) })  // Swift 2

let arr = map(nss, { "\($0)" })  // Swift 1

Answer 2

如果您有Set<String>，则可以使用Array构造函数：

let set: Set<String> = // ...
let strings = Array(set)

或者如果你有NSSet，有几个不同的选择：

let set: NSSet = // ...
let strings1 = set.allObjects as? [String] // or as!
let strings2 = Array(set as! Set<String>)
let strings3 = (set as? Set<String>).map(Array.init)

Answer 3

let set = NSSet(array: ["a","b","c"])
let arr = set.allObjects as! [String]

Answer 4

你可以这样做。

let set = //Whatever your set is
var array: [String] = []

for object in set {
     array.append(object as! String)
}