Cycle function that alternates between arguments on every call.

gistfile1.php

<?php
/*
 * Cycle between a series of arguments.
 *
 * Usage:
 *
 *   cycle('even', 'odd') # => 'even'
 *   cycle('even', 'odd') # => 'odd'
 *   cycle('even', 'odd') # => 'even'
 *
 */
function cycle() {
  $args = func_get_args();
  $_args = serialize($args);

  static $currents;
  if(!isset($currents)) $currents = array();
  
  if(!array_key_exists($_args, $currents)) {
    $currents[$_args] = 0;
  } else {
    $currents[$_args]++;
  }

  $index = $currents[$_args] % count($args);
  return $args[$index];
}
?>