(bool) $matchArray[$index], ARRAY_FILTER_USE_KEY ); } private static function filterByColumn(array $lookupArray, array $matchArray): array { $lookupArray = Matrix::transpose($lookupArray); if (count($matchArray) === 1) { $matchArray = array_pop($matchArray); } array_walk( $matchArray, function (&$value): void { $value = [$value]; } ); $result = self::filterByRow($lookupArray, $matchArray); return Matrix::transpose($result); } }