note 17519 added to function.preg-match

if you use preg_match in a loop where you expect only one match (on each string comparison), and wish to use all the matches collected in ($matches in the above example) do NOT assume that preg_match() increments this array and continues populating it - this is not the case. preg_match() does not use 'array_push' (or equivalent) to populate this array - it just continually writes to $matches[0]. so even if you get a match somewhere in the loop, if the last item you compare to does not match, the array will end up null.<br> as a workaround, use a comparator in your loop that checks to see if $matches[0] has a value, and if so, pushes that value onto another array:<br> /* this routine reads a directory ($dir2check) and compares * each item to a regexp, then harvests the results into * the array $matcharr. as a bonus, the value of $disp * will be equal to the number of matches found in the loop */ $dr = dir($dir2check); $matcharr = array(); while(($itm=$dr->read())) { // // this is a simple regexp that will match any file that has // 8 characters, then a dot, then 3 digits i.e. abcd_123.456 $disp += preg_match("/^\w{8}\.\d{3}$/i", $itm, $matches); // if the $matches array above has any values in it if ($matches[0]) { // // we push those values onto the array $matcharr array_push($matcharr, $matches[0]); } } $dr->close(); /* you now have 2 results: * $disp is equal to the number of matches found, * $matcharr is an array of all matches found in the loop */<br> you could also use this to create a multi-dimensional array if you expect there to be more than one match between the regexp and the string. in that case, don't use array_push($matcharr, $matches[0]); instead use array_push($matcharr, $matches);<br> then each element of $matcharr will be an array of matches.<br> -- http://www.php.net/manual/en/function.preg-match.php http://master.php.net/manage/user-notes.php?action=edit+17519 http://master.php.net/manage/user-notes.php?action=delete+17519 http://master.php.net/manage/user-notes.php?action=reject+17519