Error Identifier: notEqual.alwaysTrue

← Back to notEqual.*

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);

/** @param positive-int $i */
function doFoo(int $i): void
{
	if ($i != 0) {
		echo 'always nonzero';
	}
}

Why is it reported? #

The loose comparison using != always evaluates to true based on the types PHPStan has inferred. This means the condition is always satisfied, making it redundant, and any else branch would be dead code.

The != operator performs a loose (type-juggling) comparison. PHPStan reports this when it can determine from the types that the two values can never be loosely equal, regardless of the actual runtime values.

In the example above, $i is a positive-int (always >= 1), so $i != 0 is always true.

How to fix it #

Remove the redundant condition:

 /** @param positive-int $i */
 function doFoo(int $i): void
 {
-	if ($i != 0) {
-		echo 'always nonzero';
-	}
+	echo 'always nonzero';
 }

Or fix the comparison value so the condition becomes meaningful:

 /** @param positive-int $i */
 function doFoo(int $i): void
 {
-	if ($i != 0) {
+	if ($i != 1) {
 		echo 'not one';
 	}
 }

Consider using strict comparison (!==) instead of loose comparison, which avoids type-juggling surprises:

 /** @param positive-int $i */
 function doFoo(int $i): void
 {
-	if ($i != 0) {
+	if ($i !== 1) {
 		// ...
 	}
 }

How to ignore this error #

You can use the identifier notEqual.alwaysTrue to ignore this error using a comment:

// @phpstan-ignore notEqual.alwaysTrue
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: notEqual.alwaysTrue

Rules that report this error #

• PHPStan\Rules\Comparison\ConstantLooseComparisonRule [1]