$mysqli = new mysqli("localhost", "username", "password", "database");


$sql = "show tables";
$statement = $mysqli->prepare($sql);
$statement->execute();

$result = $statement->get_result();


while($row = $result->fetch_assoc()) {
  $tmp[] = $row;
}

for ($c = 0; $c < count($tmp); $c ++) {
  echo $tmp[$c]."<br>";

}

gives

Notice: Array to string conversion in /home/vhosts/blaue2.eu5.org/logo_ebui9.php on line 19