Literals

The literals section decides how values are written directly in the code: arrays as [] instead of array(), the quotes around strings, digit separators like 1_000_000, a heredoc without interpolation as a nowdoc, two strings joined with a dot on one line, and a class name in a string.

The key quotes applies only to a plain string, that is, a string without an interpolated variable, without an escape sequence that only double quotes understand, and without a quote of the target kind inside. For all other strings, the kind of quotes matters, and they stay as they are.

literals:
	arraySyntax:
		array: short
	quotes: single
	digitSeparator:
		integer: required
	digitSeparatorMinDigits:
		integer: 7
	concatenatedLiterals: forbidden

$colors = array("red", "green");  // The array must be written `[…]` instead of `array(…)`. // A plain string must be written with single quotes. // A plain string must be written with single quotes.
$limit = 1000000;  // The number `1000000` must be written `1_000_000`.
$query = 'SELECT * ' . 'FROM users';  // Useless concatenation of two string literals, because they make one literal.
$greeting = "Hello $name";

$colors = ['red', 'green'];
$limit = 1_000_000;
$query = 'SELECT * FROM users';
$greeting = "Hello $name";

The string with a variable stays in double quotes, because they change its meaning.

literals.arraySyntax.array

The syntax of an array.

short: [1, 2], never array(1, 2)
long: array(1, 2), never [1, 2]
keep: nothing is enforced, the code stays as it is

Default keep · standards: perCs short, psr12 keep, nette short, symfony short, laravel short · covers array_syntax, Generic.Arrays.DisallowLongArraySyntax, Generic.Arrays.DisallowShortArraySyntax

literals.arraySyntax.list

The syntax of a destructuring.

short: [$a, $b] =, never list($a, $b) =
long: list($a, $b) =, never [$a, $b] =
keep: nothing is enforced, the code stays as it is

Default keep · standards: perCs keep, psr12 keep, nette short, symfony keep, laravel short · covers list_syntax, SlevomatCodingStandard.PHP.ShortList

literals.classNameInString

'Acme\Shop\Order' is Order::class.

forbidden: never there
keep: nothing is enforced, the code stays as it is

Default keep · needs types · standards: perCs keep, psr12 keep, nette forbidden, symfony keep, laravel keep · covers class_keyword

A class name in a string is rewritten to ::class only when a class, interface or enum of that name really exists in the project; DressCode finds that out from types from PHPStan. The name of a trait is not rewritten, and neither is a string with a leading backslash ('\Acme\Shop\Order'), a backslash that a class name in a string does not need. A class declared in a .phpt test counts only in that file, because no autoloader loads such a test. According to its own documentation, the PHP CS Fixer rule class_keyword cannot tell this, because with tokens alone it does not know which classes the project has.

literals.implicitBackslash

A backslash of a string that escapes nothing, written \\ instead.

forbidden: never there
keep: nothing is enforced, the code stays as it is

Default keep · standards: perCs keep, psr12 keep, nette forbidden, symfony keep, laravel keep · covers escape_implicit_backslashes, string_implicit_backslashes

literals.heredocWithoutInterpolation

A heredoc with nothing to interpolate, which is written as a nowdoc.

forbidden: never there
keep: nothing is enforced, the code stays as it is

Default keep · standards: perCs forbidden, psr12 keep, nette forbidden, symfony keep, laravel forbidden · covers heredoc_to_nowdoc, SlevomatCodingStandard.PHP.RequireNowdoc

literals.digitSeparator.integer

The separator grouping by three the digits of a decimal integer, or of the integer part of a decimal number, 1_000; a number grouped already stays.

required: always there
forbidden: never there
keep: nothing is enforced, the code stays as it is

Default keep · standards: perCs keep, psr12 keep, nette required, symfony keep, laravel keep · covers PhpCsFixerCustomFixers/numeric_literal_separator, numeric_literal_separator, SlevomatCodingStandard.Numbers.DisallowNumericLiteralSeparator, SlevomatCodingStandard.Numbers.RequireNumericLiteralSeparator

literals.digitSeparator.fraction

The separator grouping by three the digits of the fraction of a decimal number, 0.000_1.

required: always there
forbidden: never there
keep: nothing is enforced, the code stays as it is

literals.digitSeparatorMinDigits.integer

The number of digits from which literals.digitSeparator.integer groups them.

a number from 1

Default 4 · standards: perCs 4, psr12 4, nette 7, symfony 4, laravel 4 · covers SlevomatCodingStandard.Numbers.RequireNumericLiteralSeparator

literals.digitSeparatorMinDigits.fraction

The number of digits from which literals.digitSeparator.fraction groups them.

a number from 1

Default 4 · standards: perCs 4, psr12 4, nette 20, symfony 4, laravel 4 · covers SlevomatCodingStandard.Numbers.RequireNumericLiteralSeparator

literals.quotes

The quotes of a plain string, one without interpolation, without an escape sequence only double quotes know and without a quote of the wanted kind inside.

single: 'text' where double quotes gain nothing
double: "text" for every plain string, the backslashes of a single-quoted one escaped
keep: nothing is enforced, the code stays as it is

Default keep · standards: perCs keep, psr12 keep, nette single, symfony single, laravel single · covers single_quote, Squiz.Strings.DoubleQuoteUsage

literals.concatenatedLiterals

Two string literals concatenated on one line, which are one literal, 'ab' for 'a' . 'b'.

forbidden: never there
keep: nothing is enforced, the code stays as it is

Default keep · standards: perCs keep, psr12 keep, nette forbidden, symfony keep, laravel keep · covers PhpCsFixerCustomFixers/no_superfluous_concatenation, no_useless_concat_operator, Generic.Strings.UnnecessaryStringConcat

literals.concatenatedLiteralsOverLines

Whether two string literals concatenated over a line break are one literal too.

yes or no

Default no · standards: perCs no, psr12 no, nette no, symfony no, laravel no · covers Generic.Strings.UnnecessaryStringConcat

literals.emptyStringConcatenation

The concatenation with an empty string, which is a cast or nothing, (string) $x for $x . ''.

forbidden: never there
keep: nothing is enforced, the code stays as it is