<?php
    class User {

        public $save_username;
        public $save_password;
        public $username;
        public $password;

        public function __construct($save_username, $save_password) {
            $this->save_username = $save_username;
            $this->save_password = $save_password;
        }

        public function login($username, $password) {
            $this->username = $username;
            $this->password = $password;

            if ($this->username == $this->save_username && $this->password == $this->save_password) {
                echo "Your username is $username and password is $password.";
                echo "<br>";
            }
            else {
                die('Error!');
            }
        }

        public function setType($type) {
            $this->type = $type;
            if($type) {
                return $type;
            }
            return 0;
        }
    }

$silviu = new User("Silviu", "1234");
$silviu->login("Silviu", "1234");



class Admin extends User{
    public $superiority;

    public function setAdmin() {
        $superiority = $this->type;
        if($superiority) {
            echo "Admin with type: $superiority.";
        }
        else {
            echo "No superior user there!";
        }
    }

}

$adina = new Admin("Adina", "1234");
$adina->login("Adina", "1234");
$adina->setType(1);
$adina->setAdmin();
?>