CodeIgniter Class Constructors

If you intend to use a constructor in any of your Controllers, you MUST place the following line of code in it:

parent::__construct();

The reason this line is necessary is because your local constructor will be overriding the one in the parent controller class so we need to manually call it.

Example:

<?php
class Blog extends CI_Controller {

        public function __construct()
        {
                parent::__construct();
                // Your own constructor code
        }
}

Constructors are useful if you need to set some default values, or run a default process when your class is instantiated. Constructors can’t return a value, but they can do some default work.