How to use preg_match to validate variables?

Hello,

I have used preg_match in the past to validate a variable by check that it only has numbers and letters. The problem is that I not longer remember what the code was.

Does any one know how to use preg_match to only allow numbers and letters in the variable?

Thanks!
Jay S.

 

All you need is here http://php.net/manual/en/function.preg-match.php

 

Better using ctype_alnum in this case.

p.p.:

if (preg_match('#^\w+$#us',$string)) echo $string." consists of all letters or digits";

Code (markup):

 

\w also includes underscores.

 

Thanks for remark
Correct:

if (preg_match('#^[a-z0-9]+$#ius',$string)) echo $string." consists of all letters or digits";

PHP: