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. The same checks can also be applied to type hints inside @param, @return, @var, @property and @property-read annotations by enabling enableForDocComments.

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.
• enableForDocComments: true also applies the configured checks to type hints in doc-comment annotations. Disabled by default.
• 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 🔧

Deprecated. Use SlevomatCodingStandard.TypeHints.DNFTypeHintFormat with nullPosition set to last and enableForDocComments set to true, which enforces the same rule for both PHP code and annotations.

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.