return everything before a certain character?

If I have a string that looks like this: x.php?0=1

Is there a way that I can return just the "1". The x.php?0= will change, so I won't be sure what it is exactly.

The title of your question and your post don't really help but this will maybe do what it is you want if all you want to do is return the 1

<?php 
$string="x.php?0=1";
$string2=preg_match("/1/","$string");
echo $string2;//returns 1
echo $string;//returns the original x.php?0=1
 ?>

Or use "strrchr()":

$str = 'x.php?0=1';
$value = substr(strrchr($str, '='), 1);