array_key_split()

array_key_split.php

/*
 * supply an array with integer and string indexes
 * and get an associative array divided into #string & #integer
 * or if a key_type argument is supplied then get an array with only the keys that match it
 *
 * arguments:
 *  $key_type is optional, and may be 'integer' or 'string'
 *
 * for use by process_tested_class()
 */
function array_key_split($array, $key_type = NULL) {
  $return_array = FALSE;
  $integer_keys = array();
  $string_keys = array();

  foreach($array as $key => $value) {
    if (is_numeric($key)) { // perhaps a test for integers is slower than a numeric test
      $integer_keys[] = $value;
    } else {
      $string_keys[$key] = $value;
    }
  }

  if (empty($key_type)) {
    $return_array = array ();
    $return_array['integer'] = $integer_keys;
    $return_array['string'] = $string_keys;
  } else {
    if ($key_type == 'integer') {
      $return_array = $integer_keys;
    } elseif ($key_type == 'string') {
      $return_array = $string_keys;
    }
  }

  return $return_array;
};