Swift2中的String與Character

從Swift2開始，String不再遵守CollectionType協議，即不再是集合類型，但是String的屬性characters遵守CollectionType協議。

String的characters屬性的類型是CharacterView(結構體)

獲取字符串String中單獨的字符Character：

for character in "Dog".characters {
    print(character)
}

使用Character類型的數組構造字符串String：

let catCharacters: [Character] = ["C", "a", "t", "!"]
let catString = String(catCharacters)

將字符串String轉化爲字符數組[Character]：

let string: String = "abcdefg"
var characters = [Character]()
for character in string.characters {
    characters.append(character)
}