使用swift

Question

所以，如果我有一个字符串数组，并且我想提取所有整数（如String s），我该怎么做？

例如：

myArray = ["1","2","3","unknown","bob"]

我试过

myArray.filter { Int($0) }

但我收到错误消息，告诉我我无法将Int?转换为Bool

Answer 1

你几乎拥有它。

Swift 3

let filteredArray = myArray.filter { Int($0) != nil }

Answer 2

简单地说，就像这样：

let myArray = ["1","2","3","unknown","bob"]
let filteredArray = myArray.filter { Int($0) != nil }
print(filteredArray) // ["1", "2", "3"]

请注意，filteredArray为[String]。要将其设为[Int]，您应该使用 map ：

let filteredArray = myArray.filter { (Int($0) != nil) }.map { Int($0)! }
print(filteredArray) // [1, 2, 3]

Answer 3

如果您只想保留可以成功转换的整数，请使用flatMap：

let strings = ["1", "2", "3", "unknown", "bob"]
let numbers = strings.flatMap{ Int($0) } // => [1, 2, 3]