2 Steps to know whether vistors use mobile to visit your website in PHP

As a website designer, when we are designing our website, we should know whether people are using mobile ,pad or pc to visit our website, then our website can display them different scale page, mobile is small, pad is media and at last display big page in pc.

To answer this question we can use php, if your website is built by php, you can do like these two steps.

Step 1: Create a php function to check visitor are using mobile

To create a php function which can tell you whether visitors are using mobile or not, you can use code below:

function is_mobile_request()
{
 $_SERVER['ALL_HTTP'] = isset($_SERVER['ALL_HTTP']) ? $_SERVER['ALL_HTTP'] : '';
 $mobile_browser = '0';
 if(preg_match('/(up.browser|up.link|mmp|symbian|smartphone|midp|wap|phone|iphone|ipad|ipod|android|xoom)/i', strtolower($_SERVER['HTTP_USER_AGENT'])))
 $mobile_browser++;
 if((isset($_SERVER['HTTP_ACCEPT'])) and (strpos(strtolower($_SERVER['HTTP_ACCEPT']),'application/vnd.wap.xhtml+xml') !== false))
 $mobile_browser++;
 if(isset($_SERVER['HTTP_X_WAP_PROFILE']))
 $mobile_browser++;
 if(isset($_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') !== false)
 $mobile_browser++;
 // Pre-final check to reset everything if the user is on Windows
 if(strpos(strtolower($_SERVER['HTTP_USER_AGENT']), 'windows') !== false)
 $mobile_browser=0;
 // But WP7 is also Windows, with a slightly different characteristic
 if(strpos(strtolower($_SERVER['HTTP_USER_AGENT']), 'windows phone') !== false)
 $mobile_browser++;
 if($mobile_browser>0)
 return true;
 else
 return false;
}