Error Identifier: logicalOr.alwaysFalse

← Back to logicalOr.*

Every error reported by PHPStan has an error identifier. Here’s a list of all error identifiers. In PHPStan Pro you can see the error identifier next to each error and filter errors by their identifiers.

Code example #

<?php declare(strict_types = 1);

function doFoo(int $x): void
{
	if ($x !== 0) {
		return;
	}

	// At this point $x is 0
	if (($x > 0) or ($x < 0)) { // ERROR: Result of or is always false.
		echo 'nonzero';
	}
}

Why is it reported? #

PHPStan determined that the result of the or expression is always false. Both comparisons evaluate to false for the narrowed type of $x, making the entire expression always false. This usually indicates dead code, a logic error, or a condition that has already been checked earlier in the control flow.

The or keyword is the low-precedence version of ||. This identifier specifically covers the or keyword; for ||, see booleanOr.alwaysFalse.

How to fix it #

Remove the redundant condition since the variable has already been narrowed:

 function doFoo(int $x): void
 {
 	if ($x !== 0) {
 		return;
 	}

-	if (($x > 0) or ($x < 0)) {
-		echo 'nonzero';
-	}
+	echo 'zero';
 }

Or fix the logic to test what was actually intended:

 function doFoo(int $x): void
 {
-	if ($x !== 0) {
+	if ($x > 10) {
 		return;
 	}

-	if (($x > 0) or ($x < 0)) {
+	if (($x > 5) or ($x < 0)) {
 		echo 'nonzero';
 	}
 }

How to ignore this error #

You can use the identifier logicalOr.alwaysFalse to ignore this error using a comment:

// @phpstan-ignore logicalOr.alwaysFalse
codeThatProducesTheError();

You can also use only the identifier key to ignore all errors of the same type in your configuration file in the ignoreErrors parameter:

parameters:
	ignoreErrors:
		-
			identifier: logicalOr.alwaysFalse

Rules that report this error #

• PHPStan\Rules\Comparison\BooleanOrConstantConditionRule [1]