1
function switchLetterCase2(s) {
2
  let res = "";
3

4
  s.split('').forEach((letter) => {
5
    const asciiCode = letter.charCodeAt(0);
6
    if ((asciiCode > 64) & (asciiCode < 91)) {
7
      res += letter.toLowerCase();
8
    } else if ((asciiCode > 96) & (asciiCode < 123)) {
9
      res += letter.toUpperCase();
10
    } else {
11
      res += letter;
12
    }
13
  });
14

15
  return res;
16
}
17

18
console.log(switchLetterCase2('ASCII'))
19

20

21
```js