Error Identifier: isset.expr

← Back to isset.*

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 function getValue(): int
	{
		return 5;
	}
}

function doFoo(Foo $foo): void
{
	if (isset($foo->getValue())) {
		echo $foo->getValue();
	}
}

Why is it reported? #

The expression inside isset() is never null based on the types PHPStan has inferred, so the isset() check is unnecessary – it will always evaluate to true. In the example above, getValue() returns int, which cannot be null, so isset($foo->getValue()) serves no purpose.

How to fix it #

Remove the unnecessary isset() check if the expression is always non-null:

 function doFoo(Foo $foo): void
 {
-	if (isset($foo->getValue())) {
-		echo $foo->getValue();
-	}
+	echo $foo->getValue();
 }

If the return value should be nullable, update the return type:

-	public function getValue(): int
+	public function getValue(): ?int
 	{
 		return 5;
 	}

How to ignore this error #

You can use the identifier isset.expr to ignore this error using a comment:

// @phpstan-ignore isset.expr
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: isset.expr

Rules that report this error #

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