Rule no_unset_cast Variables must be set null instead of using (unset) casting. Examples Example #1 --- Original +++ New <?php -$a = (unset) $b; +$a = null; Rule sets The rule is part of the following rule sets: @PHP80Migration @PHP81Migration @PHP82Migration @PHP83Migration @PhpCsFixer @Symfony Source class PhpCsFixer\Fixer\CastNotation\NoUnsetCastFixer