PHP gets/sets the language class of the user access page

<?php
/** User Language Class 获取/设置用户访问的页面语言，如果用户没有设置访问语言，则读取Accept-Language
*   Date:   2014-05-26
*   Author: fdipzone
*   Ver:    1.0
*
*   Func:
*   public  get               获取用户访问语言
*   public  set               设置用户访问语言
*   private getAcceptLanguage 获取HTTP_ACCEPT_LANGUAGE
*/

class UserLang{ // class start

    private $name = &#39;userlang&#39;; // cookie name
    private $expire = 2592000;  // cookie expire 30 days


    /** 初始化
    * @param String $name   cookie name
    * @param int    $expire cookie expire
    */
    public function __construct($name=&#39;&#39;, $expire=null){

        // 设置cookie name
        if($name!=&#39;&#39;){
            $this->name = $name;
        }

        // 设置cookie expire
        if(is_numeric($expire) && $expire>0){
            $this->expire = intval($expire);
        }

    }


    /** 获取用户访问语言 */
    public function get(){

        // 判断用户是否有设置过语言
        if(isset($_COOKIE[$this->name])){
            $lang = $_COOKIE[$this->name];
        }else{
            $lang = $this->getAcceptLanguage();
        }

        return $lang;

    }


    /** 设置用户访问语言
    * @param String $lang 用户访问语言
    */
    public function set($lang=&#39;&#39;){

        $lang = strtolower($lang);

        // 只能是英文，简体中文，繁体中文
        if(in_array($lang, array(&#39;en&#39;,&#39;sc&#39;,&#39;tc&#39;))){
            setcookie($this->name, $lang, time()+$this->expire);
        }

    }


    /** 获取HTTP_ACCEPT_LANGUAGE */
    private function getAcceptLanguage(){

        $lang = strtolower($_SERVER[&#39;HTTP_ACCEPT_LANGUAGE&#39;]);

        if(in_array(substr($lang,0,5), array(&#39;zh-tw&#39;,&#39;zh_hk&#39;))){
            $lang = &#39;tc&#39;;
        }elseif(in_array(substr($lang,0,5), array(&#39;zh-cn&#39;,&#39;zh-sg&#39;))){
            $lang = &#39;sc&#39;;
        }else{
            $lang = &#39;en&#39;;
        }

        return $lang;

    }


} // class end

?>

<?php

require "UserLang.class.php";

$obj = new UserLang(&#39;sitelang&#39;, 3600);
echo $obj->get().&#39;<br>&#39;;

?>