type-hints.md

Type hints

SlevomatCodingStandard.TypeHints.ClassConstantTypeHint 🔧

• Checks for missing typehints in case they can be declared natively.
• Reports useless @var annotation (or whole documentation comment) because the type of constant is always clear.

Sniff provides the following settings:

• enableNativeTypeHint: enforces native typehint. It's on by default if you're on PHP 8.3+
• fixableNativeTypeHint: (default: yes) allows fixing native type hints. Use no to disable fixing, or private to fix only private constants (safer for inheritance/interface compatibility).

SlevomatCodingStandard.TypeHints.DeclareStrictTypes 🔧

Enforces having declare(strict_types = 1) at the top of each PHP file. Allows configuring how many newlines should be between the <?php opening tag and the declare statement.

Sniff provides the following settings:

• declareOnFirstLine: requires declare on the first line right after <?php
• linesCountBeforeDeclare: allows to set 0 to N lines to be between declare and previous statement. This option is ignored when declareOnFirstLine is enabled.
• linesCountAfterDeclare: allows to set 0 to N lines to be between declare and next statement
• spacesCountAroundEqualsSign: allows to set number of required spaces around the = operator

SlevomatCodingStandard.TypeHints.DisallowArrayTypeHintSyntax 🔧

Disallows usage of array type hint syntax (e.g. int[], bool[][]) in phpDocs in favour of generic type hint syntax (eg. array<int>, array<array<bool>>).

Sniff provides the following settings:

• traversableTypeHints: helps fixer detect traversable type hints so \Traversable|int[] can be converted to \Traversable<int>.

SlevomatCodingStandard.TypeHints.DisallowMixedTypeHint

Disallows usage of "mixed" type hint in phpDocs.

SlevomatCodingStandard.TypeHints.DNFTypeHintFormat 🔧

Checks format of DNF type hints.

Sniff provides the following settings:

• enable: either to enable or not this sniff. By default, it is enabled for PHP versions 8.0 or higher.
• withSpacesAroundOperators: yes requires spaces around | and &, no requires no space around |and &. None is set by default so both are enabled.
• withSpacesInsideParentheses: yes requires spaces inside parentheses, no requires no spaces inside parentheses. None is set by default so both are enabled.
• shortNullable: yes requires usage of ? for nullable type hint, no disallows it. None is set by default so both are enabled.
• nullPosition: first requires null on first position in the type hint, last requires last position. None is set by default so null can be everywhere.

SlevomatCodingStandard.TypeHints.LongTypeHints 🔧

Enforces using shorthand scalar typehint variants in phpDocs: int instead of integer and bool instead of boolean. This is for consistency with native scalar typehints which also allow shorthand variants only.

SlevomatCodingStandard.TypeHints.NullTypeHintOnLastPosition 🔧

Enforces null type hint on last position in annotations.

SlevomatCodingStandard.TypeHints.NullableTypeForNullDefaultValue 🔧🚧

Checks whether the nullablity ? symbol is present before each nullable and optional parameter (which are marked as = null):

function foo(
	int $foo = null, // ? missing
	?int $bar = null // correct
) {

}

SlevomatCodingStandard.TypeHints.ParameterTypeHint 🔧🚧

• Checks for missing parameter typehints in case they can be declared natively. If the phpDoc contains something that can be written as a native PHP 7.0+ typehint, this sniff reports that.
• Checks for useless @param annotations. If the native method declaration contains everything and the phpDoc does not add anything useful, it's reported as useless and can optionally be automatically removed with phpcbf.
• Forces to specify what's in traversable types like array, iterable and \Traversable.

Sniff provides the following settings:

• enableObjectTypeHint: enforces to transform @param object into native object typehint. It's on by default if you're on PHP 7.2+
• enableMixedTypeHint: enforces to transform @param mixed into native mixed typehint. It's on by default if you're on PHP 8.0+
• enableUnionTypeHint: enforces to transform @param string|int into native string|int typehint. It's on by default if you're on PHP 8.0+
• enableIntersectionTypeHint: enforces to transform @param Foo&Bar into native Foo&Bar typehint. It's on by default if you're on PHP 8.1+
• enableStandaloneNullTrueFalseTypeHints: enforces to transform @param true, @param false or @param null into native typehints. It's on by default if you're on PHP 8.2+
• traversableTypeHints: enforces which typehints must have specified contained type. E.g. if you set this to \Doctrine\Common\Collections\Collection, then \Doctrine\Common\Collections\Collection must always be supplied with the contained type: \Doctrine\Common\Collections\Collection|Foo[].

This sniff can cause an error if you're overriding or implementing a parent method which does not have typehints. In such cases add #[Override] attribute or @phpcsSuppress SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingNativeTypeHint annotation to the method to have this sniff skip it.

SlevomatCodingStandard.TypeHints.ParameterTypeHintSpacing 🔧

• Checks that there's a single space between a typehint and a parameter name: Foo $foo
• Checks that there's no whitespace between a nullability symbol and a typehint: ?Foo

SlevomatCodingStandard.TypeHints.PropertyTypeHint 🔧🚧

• Checks for missing property typehints in case they can be declared natively. If the phpDoc contains something that can be written as a native PHP 7.4+ typehint, this sniff reports that.
• Checks for useless @var annotations. If the native method declaration contains everything and the phpDoc does not add anything useful, it's reported as useless and can optionally be automatically removed with phpcbf.
• Forces to specify what's in traversable types like array, iterable and \Traversable.

Sniff provides the following settings:

• enableNativeTypeHint: enforces to transform @var int into native int typehint. It's on by default if you're on PHP 7.4+
• enableMixedTypeHint: enforces to transform @var mixed into native mixed typehint. It's on by default if you're on PHP 8.0+. It can be enabled only when enableNativeTypeHint is enabled too.
• enableUnionTypeHint: enforces to transform @var string|int into native string|int typehint. It's on by default if you're on PHP 8.0+. It can be enabled only when enableNativeTypeHint is enabled too.
• enableIntersectionTypeHint: enforces to transform @var Foo&Bar into native Foo&Bar typehint. It's on by default if you're on PHP 8.1+. It can be enabled only when enableNativeTypeHint is enabled too.
• enableStandaloneNullTrueFalseTypeHints: enforces to transform @var true, @var false or @var null into native typehints. It's on by default if you're on PHP 8.2+. It can be enabled only when enableNativeTypeHint is enabled too.
• traversableTypeHints: enforces which typehints must have specified contained type. E.g. if you set this to \Doctrine\Common\Collections\Collection, then \Doctrine\Common\Collections\Collection must always be supplied with the contained type: \Doctrine\Common\Collections\Collection|Foo[].

This sniff can cause an error if you're overriding parent property which does not have typehints. In such cases add #[Override] attribute if you are using PHP 8.5+ or add @phpcsSuppress SlevomatCodingStandard.TypeHints.PropertyTypeHint.MissingNativeTypeHint annotation to the property to have this sniff skip it.

SlevomatCodingStandard.TypeHints.ReturnTypeHint 🔧🚧

• Checks for missing return typehints in case they can be declared natively. If the phpDoc contains something that can be written as a native PHP 7.0+ typehint, this sniff reports that.
• Checks for useless @return annotations. If the native method declaration contains everything and the phpDoc does not add anything useful, it's reported as useless and can optionally be automatically removed with phpcbf.
• Forces to specify what's in traversable types like array, iterable and \Traversable.

Sniff provides the following settings:

• enableObjectTypeHint: enforces to transform @return object into native object typehint. It's on by default if you're on PHP 7.2+
• enableStaticTypeHint: enforces to transform @return static into native static typehint. It's on by default if you're on PHP 8.0+
• enableMixedTypeHint: enforces to transform @return mixed into native mixed typehint. It's on by default if you're on PHP 8.0+
• enableUnionTypeHint: enforces to transform @return string|int into native string|int typehint. It's on by default if you're on PHP 8.0+.
• enableIntersectionTypeHint: enforces to transform @return Foo&Bar into native Foo&Bar typehint. It's on by default if you're on PHP 8.1+.
• enableNeverTypeHint: enforces to transform @return never into native never typehint. It's on by default if you're on PHP 8.1+.
• enableStandaloneNullTrueFalseTypeHints: enforces to transform @return true, @return false or @return null into native typehints. It's on by default if you're on PHP 8.2+.
• traversableTypeHints: enforces which typehints must have specified contained type. E.g. if you set this to \Doctrine\Common\Collections\Collection, then \Doctrine\Common\Collections\Collection must always be supplied with the contained type: \Doctrine\Common\Collections\Collection|Foo[].

You can add @phpcsSuppress SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingNativeTypeHint annotation to the method to skip the check.

SlevomatCodingStandard.TypeHints.ReturnTypeHintSpacing 🔧

Enforces consistent formatting of return typehints, like this:

function foo(): ?int

Sniff provides the following settings:

• spacesCountBeforeColon: the number of spaces expected between closing brace and colon.

SlevomatCodingStandard.TypeHints.UnionTypeHintFormat 🔧

Checks format of union type hints.

Sniff provides the following settings:

• enable: either to enable or not this sniff. By default, it is enabled for PHP versions 8.0 or higher.
• withSpaces: yes requires spaces around |, no requires no space around |. None is set by default so both are enabled.
• shortNullable: yes requires usage of ? for nullable type hint, no disallows it. None is set by default so both are enabled.
• nullPosition: first requires null on first position in the type hint, last requires last position. None is set by default so null can be everywhere.

SlevomatCodingStandard.TypeHints.UselessConstantTypeHint 🔧

Reports useless @var annotation (or whole documentation comment) for constants because the type of constant is always clear.