stripping all but numbers

[kingb00zer]

Hi I am attempting to strip the letters from certain input boxes within my website and seem to have a hard time understanding how preg_replace works. Here is the code I have;

$x= $_POST['inputdata'];$y= preg_replace("[^0-9]", "", $x);

The letters wont strip from the input box and I cant work out why.

[niche]

Always check the manual http://us3.php.net/m...reg-replace.php I've also found this site to be helpful http://www.regular-expressions.info/charclass.html

Edited October 28, 2012 by niche

[Ingolme]

The regular expression is missing delimiters.Try this:$y= preg_replace("/[^0-9]/", "", $x);