- preg_match: documentation ( source)
<?
echo "-";
if(preg_match('[0-9a-zA-Z]', 'bob'))
{ echo preg_match('[0-9a-zA-Z]', 'bob'); }
echo "-";
if(preg_match('~[0-9a-zA-Z]~', 'bob'))
{ echo preg_match('[0-9a-zA-Z]', 'bob'); }
echo "-";
if(preg_match('~[0-9a-zA-Z]+~', 'bob'))
{ echo preg_match('[0-9a-zA-Z]', 'bob'); }
?>