Codeigniter abstract class example

Abstract classes are special because they can never be instantiated. Instead, you typically inherit a set of base functionality from them in a new class. For that reason, they are commonly used as the base classes in a larger class hierarchy.

<?php
/**
* Created by PhpStorm.
* User: Manikanta
* Date: 10/20/2015
* Time: 6:48 PM
*/
abstract class User extends CI_Controller{
     public $name;
     public $mobile;
     public $email;
     function show(){
        echo $this->name;
     }
}
class Vendor extends User{
   function __construct(){
        parent::__construct();
   }
   function index(){
        $this->name="Mani";
        parent::show();
   }

}