Online PHP editor | output for I2XW1

<?php class User { private $username; protected $password; function __construct(){ $this->username = 'test'; } public function login() { return 'login'; } public function register() { return 'register'; } } class Teacher extends User { public $id; public $name; public $description; public $email; public $phone; function __construct(){ parent::__construct(); } public function getUsername() { return $this->username; } public function getPassword() { return $this->password; } } $o = new Teacher(); var_dump($o->getUsername());