char[] chars = string.toCharArray();
for(int i = 0; i < chars.length; i++) {
  chars[i] += 2;
}
String result = new String(chars);

char[] chars = string.toCharArray();
for(int i = 0; i < chars.length; i++) {
  chars[i] += 2;
}
String result = new String(chars);