Multiple HTTP GET parameters with the same identifier

If you can change the field name to include [], then PHP will create an array containing all of the matching values:

http://www.example.com/index.php?id[]=123&version[]=3&id[]=234&version[]=4

If you don't have the ability to change the field names, then as you say, you'll have to parse the querystring yourself.

Assuming you have some control over the request, suffix the name with [] and PHP will generate arrays instead of dropping all but one.

http://www.example.com/index.php?id[]=123&version[]=3&id[]=234&version[]=4

Since they are pairs you'll probably want to fix the order they appear in using indexes.

http://www.example.com/index.php?id[0]=123&version[0]=3&id[1]=234&version[1]=4

Just extract the keys and values of $_GET, use the function as:

print_array('$_GET...',$_GET);

... and the function code will be:

function print_array($title, $arr) {
    echo '<table width="100%" style="padding:10;">';
    echo '<tr><td width="30%" style="text-align:right; background-color:bisque;">key of </td><td style="background-color:bisque;">'.$title.'</td></tr>';
    foreach($arr as $key => $value) {
        echo '<tr>';
            echo '<td style="text-align:right; color:grey;">';
                echo $key;
            echo '</td>';
            echo '<td>';
                echo $value;
            echo '</td>';
        echo '</tr>';
    }
    echo '</table>';
}

Not as rounded or reliable as methods mentioned above but I use this to remove the need to [] in urls without worrying about rewriting.

$aQuery = explode("&", $_SERVER['QUERY_STRING']);
$aQueryOutput = array();
foreach ($aQuery as $param) {
    if(!empty($param)){
        $aTemp = explode('=', $param, 2);
        if(isset($aTemp[1]) && $aTemp[1] !== ""){
            list($name, $value) = explode('=', $param, 2);
            $aQueryOutput[ strtolower(urldecode($name)) ][] = urldecode(preg_replace('/[^a-z 0-9\'+-]/i', "", $value));
        }
    }
}