mul.rightNonNumeric

Code example

<?php declare(strict_types = 1);

function multiply(int $a, bool $flag): int
{
	return $a * $flag;
}

Why is it reported?

This rule is part of phpstan-strict-rules.

The right operand of the multiplication operator (*) is not a numeric type. PHP will attempt to cast non-numeric values to numbers, which can lead to unexpected results or warnings. Strict rules require that only numeric types are used in arithmetic operations.

How to fix it

Ensure the operand is a numeric type:

-function multiply(int $a, bool $flag): int
+function multiply(int $a, int $b): int
 {
-	return $a * $flag;
+	return $a * $b;
 }

Or explicitly cast the value:

 function multiply(int $a, bool $flag): int
 {
-	return $a * $flag;
+	return $a * (int) $flag;
 }