从 Set 中未定义的字符串中删除字符

Version = 2.2

func removeCharactersNotInSetFromText(text: String, set: Set<Character>) -> String {
   return String(text.characters.filter { set.contains( $0) })
}

let text = "Swift 3.0 Come Out"
var chars = Set([Character]("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ".characters))
let newText = removeCharactersNotInSetFromText(text, set: chars) // "SwiftComeOut"

Version = 3.0

func removeCharactersNotInSetFromText(text: String, set: Set<Character>) -> String {
  return String(text.characters.filter { set.contains( $0) })
}

let text = "Swift 3.0 Come Out"
var chars = Set([Character]("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ".characters))
let newText = removeCharactersNotInSetFromText(text: text, set: chars)