php detects whether it is a mobile device browser

This code can detect whether the user is browsing the web using a mobile device. The verification is very complete

$mobile_browser = '0';

if(preg_match('/(up.browser|up. link|mmp|symbian|smartphone|midp|wap|phone)/i',
 strtolower($_SERVER['HTTP_USER_AGENT']))){
 $mobile_browser++;
 }

if((strpos(strtolower($_SERVER[ 'HTTP_ACCEPT']),'application/vnd.wap.xhtml+xml')>0) or
 ((isset($_SERVER['HTTP_X_WAP_PROFILE']) or isset($_SERVER['HTTP_PROFILE'])))) {
 $mobile_browser++;
 }

$mobile_ua = strtolower(substr($_SERVER['HTTP_USER_AGENT'],0,4));
$mobile_agents = array(
 'w3c ','acs-','alav', 'alca','amoi','audi','avan','benq','bird','blac',
 'blaz','brew','cell','cldc','cmd-', 'dang','doco','eric','hipt','inno',
 'ipaq','java','jigs','kddi','keji','leno','lg-c' ,'lg-d','lg-g','lge-',
 'maui','maxo','midp','mits','mmef','mobi','mot-','moto ','mwbp','nec-',
 'newt','noki','oper','palm','pana','pant','phil','play','port','prox ',
 'qwap','sage','sams','sany','sch-','sec-','send','seri','sgh-','shar',
 'sie- ','siem','smal','smar','sony','sph-','symb','t-mo','teli','tim-',
 'tosh','tsm- ','upg1','upsi','vk-v','voda','wap-','wapa','wapi','wapp',
 'wapr','webc','winw', 'winw','xda','xda-');

if(in_array($mobile_ua,$mobile_agents)){
 $mobile_browser++;
 }
if (strpos(strtolower($_SERVER['ALL_HTTP']), 'OperaMini')>0) {
 $mobile_browser++;
 }
if (strpos(strtolower($_SERVER['HTTP_USER_AGENT']),'windows')>0) {
 $mobile_browser=0;
 }


if($mobile_browser>0){
 // do something
 } else {
 // do something else
 }


?>

php