Models in ci-3

WelcomeModel .php (model):

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

class WelcomeModel extends CI_Model {

function index(){
   echo "about model";
}

}

Welcome.php (controller):

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

class Welcome extends CI_Controller {

public function index()
{
   $this->load->model('WelcomeModel'); // model name 'WelcomeModel'
   $this->WelcomeModel->index(); // WelcomeModel is modelname and index is function name
   // $this->load->view('welcome_message');
}

function about(){
  echo "about page";
}


}