我建立一個CodeIgniter 3.1.3的網站，我希望我的網站有多種語言，所以我第一次嘗試使用語言庫，通過其他網站的CI官方指南&教程，但它是不按預期工作。CodeIgniter語言類庫不工作

我application/language/english/slogan_lang.php：

$lang["slogan1"] = "A little social media but with more fun!", 
$lang["slogan2"] = "Where face and real name is not important.", 
$lang["slogan3"] = "It's a social media. Eh, it's more like a game.", 
$lang["slogan4"] = "Fantastic yet fabulous life in a screen.", 
$lang["slogan5"] = "Not just poke with one finger, you can duel!",

我controller/index：

public function index() { 
    if ($this->session->has_userdata('userid')) redirect('yay/home'); 
    if (get_cookie('remember_me')!=null) { 
     //bla bla bla 

     redirect('yay/home'); 
    } else { 
     $this->lang->load('slogan',$this->session->userdata('lang')); 
     $data = array(); 
     $data['lg_slogan'] = array(
      $this->lang->line('slogan1'), 
      $this->lang->line('slogan2'), 
      $this->lang->line('slogan3'), 
      $this->lang->line('slogan4'), 
      $this->lang->line('slogan5'), 
     ); 
     $this->load->view('index',$data); 
    } 
}

$這個 - >會話級>用戶數據（ '郎'）===> '英語'