Error Identifier: nullCoalesce.property

← Back to nullCoalesce.*

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);

class Foo
{
	public int $bar = 0;
}

function test(): void
{
	$foo = new Foo();
	$foo->bar = 5;
	echo $foo->bar ?? 0;
}

Why is it reported? #

The null coalescing operator (??) is designed to provide a fallback value when the left-hand side is null. When the property being checked is typed as non-nullable (e.g., int), it can never be null, so the fallback value on the right side of ?? will never be used. This indicates either dead code or a missing nullable type on the property.

How to fix it #

If the property is intentionally non-nullable, remove the unnecessary null coalescing operator:

 function test(): void
 {
 	$foo = new Foo();
 	$foo->bar = 5;
-	echo $foo->bar ?? 0;
+	echo $foo->bar;
 }

If the property should be nullable, update its type declaration:

 class Foo
 {
-	public int $bar = 0;
+	public ?int $bar = null;
 }

How to ignore this error #

You can use the identifier nullCoalesce.property to ignore this error using a comment:

// @phpstan-ignore nullCoalesce.property
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: nullCoalesce.property

Rules that report this error #

• PHPStan\Rules\Variables\EmptyRule [1]
• PHPStan\Rules\Variables\IssetRule [1]
• PHPStan\Rules\Variables\NullCoalesceRule [1]