How to determine whether the device is a mobile phone or tablet in php

/**
 * PHP 判断设备是否是手机还是平板的方法
 * @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;
}