继承codeigniter php中的代码

Im trying to inherit a constant var which are in another file/class. But I tried almost everything and I can't do it for some reason, can anyone tell me what is wrong or just are happening in my code please?

this is my main class that i called BasePage.

            class BasePage extends CI_Controller {

                const $TITLE = "My Own DB";

            }

and this is the other class/file which is trying to inherit to other class by giving the constant var TITLE into an array.

            <?php
            defined('BASEPATH') OR exit('No direct script access allowed');

            require 'BasePage.php';

            class Home extends BasePage {

                public function index()
                {
                    $data = array('title' => $TITLE);

                    $this->load->helper('url');
                    $this->load->view('page_login', $data);
                }
            }

The constant should not have a $ at the beginning.

And you don't access it like $TITLE, or just TITLE, but with self::TITLE. In this case it would be most correct to use parent::TITLE, since it belongs to a parent class.

This should work:

        class BasePage extends CI_Controller {

            const TITLE = "My Own DB";

        }

        <?php
        defined('BASEPATH') OR exit('No direct script access allowed');

        require 'BasePage.php';

        class Home extends BasePage {

            public function index()
            {
                $data = array('title' => parent::TITLE);

                $this->load->helper('url');
                $this->load->view('page_login', $data);
            }
        }