I needed to be able to sort a string that contained numbers eg.

"Slot 1 name"
"Slot 2 name"
"Slot 10 name"

using a normal string compare the "Slot 10 name" would appear before "Slot 2 name" so I wrote little function that will compare a string taking numbers in to consideration. There may be a few edge cases that need to be taken in to consideration.

function strCmpWithNumbers( $a, $b) {
  // Split the string in to words.
  $a = explode(' ',$a);
  $b = explode(' ',$b);
  $loop = 0;
  do {
    // Get the first word from each item
    $ta = Utils::gvfa($a, $loop);
    $tb = Utils::gvfa($b, $loop);
    
    if (isset($ta)) {
      if (isset($tb)) {
        if (is_numeric($ta)) {
          if ($ta != $tb) {
            return $ta - $tb;
          }
        } else {
          $val = strcasecmp($ta, $tb);
          if ($val != 0) {
            return $val;
          }
        }
      } else {
        return 1; // a is set but b isn't
      }
    } else {
      return isset($b);
    }
    $loop +=1;
  } while (true);
}