sample encoding shifting character type

encode shifting alphabet

/**
* note: below sample only for alphabet, because it filter by Character.isLetter
*/
private static String encode(String line) {
    char[] toEncode = line.toCharArray();
    for (int i = 0; i < toEncode.length; i++) {
        if (Character.isLetter(toEncode[i])) {
            toEncode[i] = (char) ((toEncode[i] + 1 - (int)'a') % 26 + (int)'a');
        }
    }
    line = String.valueOf(toEncode);
    return line;
}

reverse number

/**
* reverse number sample 1234 => 4321
*/
private static int reverseNumber(int num){
  int reversenum = 0;
      while( num != 0 )
      {
          reversenum = reversenum * 10;
          reversenum = reversenum + num%10;
          num = num/10;
      }
  return reversenum;
}

split number and aphabet in String

/**
* how to split number and alphabet in String using regex
*/
private static String[] splitNumberAndAphabet(String input){
  return input.split("(?<=\\D)(?=\\d)|(?<=\\d)(?=\\D)");
}