function check_date(FuelDocs $docs_en, FuelDocs $docs_ja) { foreach ($docs_en as $file => $val) { $date_en = new DateTime($docs_en->getDate($file)); $date_ja = new DateTime($docs_ja->getDate($file)); if ($date_en >= $date_ja) { echo $file, ' : en ', $date_en->format('Y-m-d H:m:s O'), ' ja ', $date_ja->format('Y-m-d H:m:s O'), PHP_EOL; $error = true; } } if ($error) { exit(1); } }