note 101147 deleted from functions.user-defined by danbrown

Note Submitter: amiller at connext dot net ---- function useful_recursion($haystack, $needle) { # Recursive implementation of in_array. # Not recommended for production use; PHP's stack is # too short. Use builtin in_array() instead. if (!is_array($haystack)) { trigger_error("First argument to useful_recursion() must be an array.", E_USER_ERROR); }; if (count($haystack) == 0) { # nothing left in the haystack, and we didn't find the needle return false; }; # take the next element of $haystack for comparison # (note that this shortens $haystack by one each time # through the function) $straw = array_pop($haystack); if ($needle == $straw) { # found it! return true; }; # this straw isn't the needle, but there's more hay in the # stack -- here's where we recur return useful_recursion($haystack, $needle); }