note 14691 added to function.array-intersect.php

<p> Concerning xx@xx.com's PHP3 array_intersect function I've got a couple improvements. First, it's much safer to walk through the arrays as linked lists using the reset() and next() functions rather than by index. Next, before doing any kind of search though an array like this you should sort the arrays first, it saves lots of time when using this function on huge arrays. So my own PHP3 version of this function would be as follows: </p> function array_intersect($array1,$array2) { // make sure arguments are actually arrays if (!is_array($array1) || !is_array($array2)) return false; if (sizeof($array2) > sizeof($array1)) { $temp = $array1; $array1 = $array2; $array2 = $temp; unset($temp); } $array1 = sort($array1); $array2 = rsort($array2); // the greatest element in array2 $eg2 = reset($array2); for ($e1=reset($array1); $e1; $e1=next($array1)) { for ($e2=reset($array2); $e2; $e2=next($array2)) { if ($e1 > $e2) { // we have passed the match if ($e2 == $eg2) break(2); else break; } else if ($e1 == $e2) { // we found a match $retArray[] = $e1; break; } } } return $retArray; } http://www.php.net/manual/en/function.array-intersect.php