简单类型 / 字符类型

let charA: Character = "A"
var utf16Value = charA.utf16.first!
//utf16Value is 66

utf16Value += 1
let charB = Character(UnicodeScalar(utf16Value)!)
//charB is "B"

print("utf16Value is \(utf16Value)")
print("charB is \(charB)")