每次有构造函数都被称为“parent :: __ construct（）; “在模型和控制器上。 为什么用它？

Question

Here is the constructor invocation. There is nothing is passed or no function is called in constructor. why it is called?

class admin_login_model extends CI_Model {

function __construct() {
    parent::__construct();
}

on controller

class admin_login extends CI_Controller {

function __construct() {
    parent::__construct();

    // if(!$this->session->userdata('validated')) redirect('admin/admin_login');
}

}

Answer 1

checking every page user session exist or not .like this .if you use the constructor .when every page calling constructor execute first and give out put true. then go to the function so that there we checking user session exist or not like this checking