postDec.nonNumeric - Phpstan

Code example

php

<?php declare(strict_types = 1);

/** @var stdClass $object */
$object--;

Why is it reported?

The post-decrement operator ($x--) is intended for numeric types. Using it on a non-numeric value such as an object, array, or non-numeric string produces unexpected results or a runtime error.

This rule is part of phpstan-strict-rules.

How to fix it

Ensure the operand is a numeric type:

diff-php

-$value--;
+$numericValue--;

If the value might be non-numeric, convert it first:

diff-php

-$value--;
+$value = ((int) $value) - 1;