McGansWebsite/application/controllers/Welcome.php

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

class Welcome extends CI_Controller {
	public function __construct()
	{
		parent::__construct();
		$this->load->model('Subject_model');
	}

	/**
	 * Index Page for this controller.
	 *
	 * Maps to the following URL
	 * 		http://example.com/index.php/welcome
	 *	- or -
	 * 		http://example.com/index.php/welcome/index
	 *	- or -
	 * Since this controller is set as the default controller in
	 * config/routes.php, it's displayed at http://example.com/
	 *
	 * So any other public methods not prefixed with an underscore will
	 * map to /index.php/welcome/<method_name>
	 * @see https://codeigniter.com/user_guide/general/urls.html
	 */
	public function index()
	{
		$data['dep']=$this->Department_model->dep_list();
		$this->load->view('index',$data);
	}
	public function subjectList($id)
	{
		$data['subject_list']=$this->Subject_model->subject_list($id);
		$this->load->view('subject_list',$data);
	}
	public function about()
	{
		$this->load->view('about');
	}
	 
}