Swift2中的String与Character

从Swift2开始，String不再遵守CollectionType协议，即不再是集合类型，但是String的属性characters遵守CollectionType协议。

String的characters属性的类型是CharacterView(结构体)

获取字符串String中单独的字符Character：

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

使用Character类型的数组构造字符串String：

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

将字符串String转化为字符数组[Character]：

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