Page 1 of 1

only allow specified characters...

Posted: Fri Jan 23, 2004 2:39 am
by lizlazloz
i tried

Code: Select all

<?php

$chars=[a-z0-9];
if ( preg_match($chars, $name) )
{
do stuff....
}

?>
but it didnt work...

Posted: Fri Jan 23, 2004 4:17 am
by twigletmac
Try:

Code: Select all

<?php

$name  = 'ted3';
$chars = 'a-z0-9';

if (preg_match('/^['.$chars.']+$/i', $name)) {
    echo 'yes';
} else {
	echo 'no';
}

?>
if you're only testing for alphanumeric characters though, you can avoid the regex and simply use [php_man]ctype_alnum[/php_man]():

Code: Select all

<?php

$name  = 'tede4$3';
$chars = 'a-z0-9';

if (ctype_alnum($name)) {
    echo 'yes';
} else {
	echo 'no';
}

?>
Mac