$re = '/param[12]=(\w+)/';
$str = 'http://example.com/conversion/?param1=dhkw121?param2=dhja143&uuid=jsbdwbjb-fwjdbw-wdvvw-wj
http:// example.com/conversion/param1=dhkw121%uuid=dbjbjbcs-fbsj-fsjbjs-fsj/param2=dhja143';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php