/**
 * Test if the current browser runs on a mobile device (smart phone, tablet, etc.)
 *
 * @staticvar bool $is_mobile
 *
 * @return bool
 */
function wp_is_mobile() {
 static $is_mobile = null;
 
 if ( isset( $is_mobile ) ) {
  return $is_mobile;
 }
 
 if ( empty($_SERVER['HTTP_USER_AGENT']) ) {
  $is_mobile = false;
 } elseif ( strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile') !== false // many mobile devices (all iPhone, iPad, etc.)
  || strpos($_SERVER['HTTP_USER_AGENT'], 'Android') !== false
  || strpos($_SERVER['HTTP_USER_AGENT'], 'Silk/') !== false
  || strpos($_SERVER['HTTP_USER_AGENT'], 'Kindle') !== false
  || strpos($_SERVER['HTTP_USER_AGENT'], 'BlackBerry') !== false
  || strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mini') !== false
  || strpos($_SERVER['HTTP_USER_AGENT'], 'Opera Mobi') !== false ) {
   $is_mobile = true;
 } else {
  $is_mobile = false;
 }
 
 return $is_mobile;
}

<?php
function is_mobile() {
$user_agent = $_SERVER['HTTP_USER_AGENT'];
$mobile_browser = Array(
"mqqbrowser", //手机QQ浏览器
"opera mobi", //手机opera
"juc","iuc",//uc浏览器
"fennec","ios","applewebKit/420","applewebkit/525","applewebkit/532","ipad","iphone","ipaq","ipod",
"iemobile", "windows ce",//windows phone
"240×320","480×640","acer","android","anywhereyougo.com","asus","audio","blackberry","blazer","coolpad" ,"dopod", "etouch", "hitachi","htc","huawei", "jbrowser", "lenovo","lg","lg-","lge-","lge", "mobi","moto","nokia","phone","samsung","sony","symbian","tablet","tianyu","wap","xda","xde","zte"
);
$is_mobile = false;
foreach ($mobile_browser as $device) {
if (stristr($user_agent, $device)) {
$is_mobile = true;
break;
}
}
return $is_mobile;
}?>

<?php if(is_mobile()):?>

<?php endif; ?>