public static function mb_convert_variables($toEncoding, $fromEncoding, &...$vars) { $ok = true; array_walk_recursive($vars, function (&$v) use (&$ok, $toEncoding, $fromEncoding) { if (false === ($v = self::mb_convert_encoding($v, $toEncoding, $fromEncoding))) { $ok = false; } }); return $ok ? $fromEncoding : false; }