note 129473 added to ref.array

Be careful with type hints in callbacks when using array-traverse functions. In some cases, this may silently cause the data type of elements to change. <?php declare(strict_types=1); // Missing fatal TypeError, No side effects $unexpected = array_filter(['123', (string) PHP_INT_MAX], fn (int $item) => true); var_dump($unexpected); // Missing fatal TypeError, Typecasting side effect $unexpectedTypecasting = array_map(fn (int $item) => $item, ['123', (string) PHP_INT_MAX]); var_dump($unexpectedTypecasting); // Missing fatal TypeError, Typecasting side effect $unexpectedTypecasting = array_map(fn (string $item) => $item, [123, PHP_INT_MAX]); var_dump($unexpectedTypecasting); // Missing fatal TypeError, Typecasting side effect $unexpectedTypecasting = array_reduce(['123', (string) PHP_INT_MAX], fn (?int $carry, int $item) => $item); var_dump($unexpectedTypecasting); $bigIntValue = bcadd((string) PHP_INT_MAX, '1'); // Fatal TypeError $expectedTypeError = array_map(fn (int $item) => $item, [$bigIntValue]); var_dump($expectedTypeError); ?> The above example will output (PHP version 8.3.6, error_reporting E_ALL): <?php array(2) { [0]=> string(3) "123" [1]=> string(19) "9223372036854775807" } array(2) { [0]=> int(123) [1]=> int(9223372036854775807) } array(2) { [0]=> string(3) "123" [1]=> string(19) "9223372036854775807" } int(9223372036854775807) Fatal error: Uncaught TypeError: {closure}(): Argument #1 ($item) must be of type int, string given ?> ---- Server IP: 45.112.84.4 Probable Submitter: 80.90.13.131 (proxied: 185.5.48.152) ---- Manual Page -- https://php.net/manual/en/ref.array.php Edit -- https://main.php.net/note/edit/129473 Del: integrated -- https://main.php.net/note/delete/129473/integrated Del: useless -- https://main.php.net/note/delete/129473/useless Del: bad code -- https://main.php.net/note/delete/129473/bad+code Del: spam -- https://main.php.net/note/delete/129473/spam Del: non-english -- https://main.php.net/note/delete/129473/non-english Del: in docs -- https://main.php.net/note/delete/129473/in+docs Del: other reasons-- https://main.php.net/note/delete/129473 Reject -- https://main.php.net/note/reject/129473 Search -- https://main.php.net/manage/user-notes.php