booleanAnd.rightAlwaysFalse

Code example

<?php declare(strict_types = 1);

function doFoo(int $i): void
{
	if ($i === 0 && $i) {

	}
}

Why is it reported?

The right side of the && (boolean AND) expression always evaluates to false. After the left side of && is evaluated, PHPStan narrows the type of the involved variables. If the right-hand side can never be truthy given that narrowed type, the entire expression is always false. In the example above, after $i === 0 passes, $i is known to be 0, which is falsy, so $i on the right side is always false. This usually indicates a logic error or dead code.

How to fix it

Fix the logic so that the right-hand side can actually be true:

 <?php declare(strict_types = 1);

 function doFoo(int $i): void
 {
-	if ($i === 0 && $i) {
+	if ($i !== 0 && $i > 5) {

 	}
 }

Or remove the expression entirely if the code block is unreachable:

 <?php declare(strict_types = 1);

 function doFoo(int $i): void
 {
-	if ($i === 0 && $i) {
-
-	}
 }