ios swift String遍历 Int Character

        let str = "123456"
        for i in str {
            let str1 = "" + String(i)
            print(str1)
            let num: Int = Int(str1)!+10
            print(num)
        }

打印：
1
11
2
12
3
13
4
14
5
15
6
16

        let str = "123456"
        for i in str.utf8 {
            print(i)//Int
            print(i+100)
        }

打印：
49
149
50
150
51
151
52
152
53
153
54
154