[Resolved] Recursion: Reverse an Integer

[The Hobo]

I need to write a recursive function to reverse the order of digits in an integer. This is a homework problem, so it has to be done using recursion (not a loop or anything). This is what I've come up with so far:

public int revDigits (int num) { 
  if (num < 10) {
      return num;
  } else {
      int s = num / 10;
      int d = num % 10;

      int i = revDigits(s);

      return (d * 10) + i; // incorrect

      // need to find out how many digits in d:
      //return (d * 10^(num digits in d)) + i);
  }
}

The problem that I've come across is commetted at the bottom. Any help with solving this would be appreciated. Thanks in advance.