Objet impossible

		#select all users in a table
		$tabUsers = Db::getInstance()->select_all_users();
		var_dump($tabUsers);

			<tbody>
				<?php for ($i = 0; count($tabUsers); $i++) { ?>
				<tr>
					<td><?php echo $tabUsers[$i]->get_pseudo() ?></td>
					<td><?php echo $tabUsers[$i]->get_mdp() ?></td>
					<td><?php echo $tabUsers[$i]->get_photo() ?></td>
				</tr>
				<?php } ?>

	public function select_all_users(){
		$query = "SELECT * FROM users";
		$result = $this->_db->query($query);

		$user = null;
		#verifier si le resultat n'est pas null ! 
		if ($result->rowcount() == null){
			return $user;
		}else{
			while ($row = $result->fetch()) {
				$user = new User($row->pseudo, $row->mdp, $row->photo);
			}
		}
		return $user;
	}