• Version: 1.0
• Voting Start: ?
• Voting End: ?
• RFC Started: 2021-12-23
• RFC Updated: 2021-12-23
• Author: Craig Francis, craig#at#craigfrancis.co.uk
• Status: ?
• First Published at: https://wiki.php.net/rfc/allow_null
• GitHub Repo: https://github.com/craigfrancis/php-allow-null-rfc
• Implementation: ?

PHP 8.1 introduced “Passing null to parameter X of type string is deprecated” with internal functions (discussion), which is making it difficult for developers to upgrade, especially for those who do not use strict_types.

Often NULL is used for undefined GET/POST/COOKIE variables:

$name = ($_POST['name'] ?? NULL);
 
$name = $request->input('name'); // Laravel
$name = $request->get('name'); // Symfony
$name = $this->request->getQuery('name'); // CakePHP
$name = $request->getGet('name'); // CodeIgniter

And NULL can be returned from many functions, e.g.

• array_pop()
• error_get_last()
• mysqli_fetch_row()
• json_decode()
• filter_input()

Currently this change only affects those using PHP 8.1 with E_DEPRECATED, but it implies everyone will need to modify their code in the future.

And those modifications are not easy (both in finding them, and quantity).

Developers will need to either use these deprecation warnings, or use strict static analysis (one that can determine when a variable can be NULL; e.g. Psalm at level 3, with no baseline).

This affects every variable that could be set to NULL, when they are passed to any internal function that has deprecated the NULL value. And every time, developers will need to change their code, typically with the seemingly pointless task of converting those NULL values to an empty string.

To make upgrading easier, we could either:

1. Allow NULL when strict_types is not being used;
2. Update some of the internal functions to accept NULL.

N/A

PHP 8.1

None known

None known

None known

TODO

TODO

Accept the RFC

TODO

TODO

TODO

TODO

---

Interesting to note that this goes against the example quote from Rasmus:

PHP is and should remain:
1) a pragmatic web-focused language
2) a loosely typed language
3) a language which caters to the skill-levels and platforms of a wide range of users

grep -h -r -E '^\s*(ZEND_FUNCTION|PHP_FUNCTION|static void)|Z_PARAM_STR\(' ./php-src/

Search

^(\s*(ZEND_FUNCTION|PHP_FUNCTION|static void).*\n)*(ZEND_FUNCTION\(|PHP_FUNCTION\(|static void *)(.+?)(\)|\().*

Replace

$4