parse_url

function convertUrlQuery($url) {
    $query = parse_url($url, PHP_URL_QUERY);
    $queryParts = explode('&', $query);
   
    $params = array();
    foreach ($queryParts as $param) {
        $item = explode('=', $param);
        if ($item[0] == "id"){
                return $item[1];
        }
        //$params[$item[0]] = $item[1];
    }
   
    return "";//$params;
}
    print_r(convertUrlQuery(''));
?>