note 92393 added to function.ctype-alnum

ctype_alnum() is a godsend for quick and easy username/data filtering when used in conjunction with str_replace(). Let's say your usernames have dash(-) and underscore(_) allowable and alphanumeric digits as well. Instead of a regex you can trade a bit of performance for simplicity: <? $sUser = 'my_username01'; $aValid = array('-', '_'); if(!ctype_alnum(str_replace($aValid), '', $sUser)) { echo 'Your username is not properly formatted.'; } ?> ---- Server IP: 209.41.74.194 Probable Submitter: 134.29.231.10 ---- Manual Page -- http://www.php.net/manual/en/function.ctype-alnum.php Edit -- https://master.php.net/note/edit/92393 Del: integrated -- https://master.php.net/note/delete/92393/integrated Del: useless -- https://master.php.net/note/delete/92393/useless Del: bad code -- https://master.php.net/note/delete/92393/bad+code Del: spam -- https://master.php.net/note/delete/92393/spam Del: non-english -- https://master.php.net/note/delete/92393/non-english Del: in docs -- https://master.php.net/note/delete/92393/in+docs Del: other reasons-- https://master.php.net/note/delete/92393 Reject -- https://master.php.net/note/reject/92393 Search -- https://master.php.net/manage/user-notes.php