The article is incorrect - the vote for that was defeated: https://wiki.php.net/rfc/engine_warnings#vote https://wiki.php.net/rfc/engine_warnings#vote Undefine

The article is incorrect - the vote for that was defeated: https://wiki.php.net/rfc/engine_warnings#vote https://wiki.php.net/rfc/engine_warnings#vote Undefined variables will now be warnings (and one might expect PHP 9 to reclassify them as exceptions).