This guide extends and expands the basic coding standard PSR-1.

The intent of this guide is to reduce cognitive friction when scanning code from different authors. It does so by enumerating a shared set of rules and expectations about how to format PHP code.

• The code MUST follow PSR-1.
• the code MUST use 4 spaces for indenting, not tabs.
• There MUST NOT be a hard limit on line length; the soft limit MUST be 120 characters; lines SHOULD be 80 characters or less.
• There MUST be one blank line after the namespace declaration, and there MUST be one blank line after the block of use declarations.
• Opening braces for classes MUST go on the next line, and closing braces MUST go on the next line after the body.
• Opening braces for methods MUST go on the next line, and closing braces MUST go on the next line after the body.
• Visibility MUST be declared on all properties and methods; abstract and final MUST be declared before the visibility; static MUST be declared after the visibility.
• Control structure keywords MUST have one space after them; method and function calls MUST NOT.
• Opening braces for control structures MUST go on the same line, and closing braces MUST go on the next line after the body.
• Opening parentheses for control structures MUST NOT have a space after them, and closing parentheses for control structures MUST NOT have a space before.

This example encompasses some of the rules below as a quick overview: <PHP> <?php namespace Vendor\Package;

use FooInterface; use BarClass as Bar; use OtherVendor\OtherPackage\BazClass;

class Foo extends Bar implements FooInterface {

  public function sampleFunction($a, $b = null)
  {
      if ($a === $b) {
          bar();
      } elseif ($a > $b) {
          $foo->bar($arg1);
      } else {
          BazClass::bar($arg2, $arg3);
      }
  }

  final public static function bar()
  {
      // method body
  }

} </PHP>

The code MUST follow all rules outlined in PSR-1.

• All PHP files MUST use the Unix LF (linefeed) line ending.
• All PHP files MUST end with a single blank line.
• The closing ?> PHP tag MUST be omitted from files containing only PHP.

• There MUST NOT be a hard limit on line length.
• The soft limit on line length MUST be 120 characters; automated style checkers MUST warn but MUST NOT error at the soft limit.
• Lines SHOULD NOT be longer than 80 characters; lines longer than that SHOULD be split into multiple subsequent lines of no more than 80 characters each.
• There MUST NOT be trailing whitespace at the end of non-blank lines.
• Blank lines MAY be added to improve readability and to indicate related blocks of code.
• There MUST NOT be more than one statement per line.

Code MUST use an indent of 4 spaces, and MUST NOT use tabs for indenting.

Using only spaces, and not mixing spaces with tabs, helps to avoid problems with diffs, patches, history, and annotations. The use of spaces also makes it easy to insert fine-grained sub-indentation for inter-line alignment.

• PHP keywords MUST be in lower case.
• The PHP constants true, false, and null MUST be in lower case.

• When present, there MUST be one blank line after the namespace declaration.
• When present, all use declarations MUST go after the namespace declaration.
• There MUST be one use keyword per declaration.
• There MUST be one blank line after the use block.

For example: <PHP> <?php namespace Vendor\Package;

use FooClass; use BarClass as Bar; use OtherVendor\OtherPackage\BazClass;

… additional PHP code … </PHP> ===== Classes, Properties, and Methods ===== The term 'class' refers to all classes, interfaces, and traits. ==== Extends and Implements ==== The extends and implements keywords MUST be declared on the same line as the class name. The opening brace for the class MUST go on its own line; the closing brace for the class MUST go on the next line after the body. <PHP> <?php namespace Vendor\Package; use FooClass; use BarClass as Bar; use OtherVendor\OtherPackage\BazClass; class ClassName extends ParentClass implements \ArrayAccess, \Countable { constants, properties, methods } </PHP> Lists of implements MAY be split across multiple lines, where each subsequent line is indented once.
When doing so, the first item in the list MUST be on the next line, and there MUST be only one interface per line. <PHP> <?php namespace Vendor\Package;

use FooClass; use BarClass as Bar; use OtherVendor\OtherPackage\BazClass;

class ClassName extends ParentClass implements

  \ArrayAccess,
  \Countable,
  \Serializable

{

  // constants, properties, methods

} </PHP>

• Visibility MUST be declared on all properties.
• The var keyword MUST NOT be used to declare a property.
• There MUST NOT be more than one property declared per statement.
• Property names SHOULD NOT be prefixed with a single underscore to indicate protected or private visibility.

A property declaration looks like the following. <PHP> <?php namespace Vendor\Package;

class ClassName {

  public $foo = null;

} </PHP>

• Visibility MUST be declared on all methods.
• Method names SHOULD NOT be prefixed with a single underscore to indicate protected or private visibility.
• Method names MUST NOT be declared with a space after the method name. The opening brace MUST go on its own line, and the closing brace MUST go on the next line following the body. There MUST NOT be a space after the opening parenthesis, and there MUST NOT be a space before the closing parenthesis.

A method declaration looks like the following. Note the placement of parentheses, commas, spaces, and braces: <PHP> <?php namespace Vendor\Package;

class ClassName {

  public function fooBarBaz($arg1, &$arg2, $arg3 = [])
  {
      // method body
  }

} </PHP>

• In the argument list, there MUST NOT be a space before each comma, and there MUST be one space after each comma.
• Method arguments with default values MUST go at the end of the argument list.

<PHP> <?php namespace Vendor\Package;

class ClassName {

  public function foo($arg1, &$arg2, $arg3 = [])
  {
      // method body
  }

} </PHP>

• Argument lists MAY be split across multiple lines, where each subsequent line is indented once. When doing so, the first item in the list MUST be on the next line, and there MUST be only one argument per line.
• When the argument list is split across multiple lines, the closing parenthesis and opening brace MUST be placed together on their own line with one space between them.

<PHP> <?php namespace Vendor\Package;

class ClassName {

  public function aVeryLongMethodName(
      ClassTypeHint $arg1,
      &$arg2,
      array $arg3 = []
  ) {
      // method body
  }

} </PHP>

• When present, the abstract and final declarations MUST precede the visibility declaration.
• When present, the static declaration MUST come after the visibility declaration.

<PHP> <?php namespace Vendor\Package;

abstract class ClassName {

  protected static $foo;

  abstract protected function zim();

  final public static function bar()
  {
      // method body
  }

} </PHP>

When making a method or function call, there MUST NOT be a space between the method or function name and the opening parenthesis, there MUST NOT be a space after the opening parenthesis, and there MUST NOT be a space before the closing parenthesis. In the argument list, there MUST NOT be a space before each comma, and there MUST be one space after each comma. <PHP> bar(); $foo→bar($arg1); Foo::bar($arg2, $arg3); </PHP>

• Argument lists MAY be split across multiple lines, where each subsequent line is indented once. When doing so, the first item in the list MUST be on the next line, and there MUST be only one argument per line.
• When splitting an argument list, the closing parenthesis MUST be on a separate line without a space character in between.

<PHP> $foo→bar(

  $longArgument,
  $longerArgument,
  $muchLongerArgument

); </PHP>

The general style rules for control structures are as follows:

• There MUST be one space after the control structure keyword
• There MUST NOT be a space after the opening parenthesis
• There MUST NOT be a space before the closing parenthesis
• There MUST be one space between the closing parenthesis and the opening brace
• The structure body MUST be indented once
• The closing brace MUST be on the next line after the body

The body of each structure MUST be enclosed by braces. This standardizes how the structures look, and reduces the likelihood of introducing errors as new lines get added to the body.

An if structure looks like the following. Note the placement of parentheses, spaces, and braces; and that else and elseif MUST be on the same line as the closing brace from the earlier body separated by one space character. <PHP> if ($expr1) {

  // if body

} elseif ($expr2) {

  // elseif body

} else {

  // else body;

} </PHP> The keyword elseif SHOULD be used instead of else if so that all control keywords look like single words.

A switch structure looks like the following. Note the placement of parentheses, spaces, and braces. The case statement MUST be indented once from switch, and the break keyword (or other terminating keyword) MUST be indented at the same level as the case body. There MUST be a comment such as // no break when 'fall-through' is intentional in a non-empty case body. <PHP> switch ($expr) {

  case 0:
      echo 'First case, with a break';
      break;
  case 1:
      echo 'Second case, which falls through';
      // no break
  case 2:
  case 3:
  case 4:
      echo 'Third case, return instead of break';
      return;
  default:
      echo 'Default case';
      break;

} </PHP>

A while statement looks like the following. Note the placement of parentheses, spaces, and braces. <PHP> while ($expr) {

  // structure body

} </PHP> Similarly, a do while statement looks like the following. Note the placement of parentheses, spaces, and braces. <PHP> do {

  // structure body;

} while ($expr); </PHP>

A for statement looks like the following. Note the placement of parentheses, spaces, and braces. <PHP> for ($i = 0; $i < 10; $i++) {

  // for body

} </PHP>

A foreach statement looks like the following. Note the placement of parentheses, spaces, and braces. <PHP> foreach ($iterable as $key ⇒ $value) {

  // foreach body

} </PHP>

Ein try catch-Statement sieht wie nachfolgend aus. Beachten Sie die Plazierung von Klammern, Leerstellen und geschweiften Klammern. <PHP> try {

  // try body

} catch (FirstExceptionType $e) {

  // catch body

} catch (OtherExceptionType $e) {

  // catch body

} </PHP>

• Closures MÜSSEN mit einem Leerzeichen nach denm Schlüsselwort function und je einem Leerzeichen vor und nach dem Schlüsselwort use deklariert werden.
• Die öffnende, geschweifte Klammer MUSS in der selben Zeile wie das Schlüsselwort function sein und die schließende Klammer MUSS in der nächsten Zeile nach dem Funktionskörper sein.
• Nach der öffnenden Klammer der Argumentenliste DARF NICHT ein Leerzeichen stehen und vor der schließenden Klammer DARF NICHT ein Leerzeichen sein.
• In der Argumentenliste und der Variablenliste DARF NICHT ein Leerzeichen vor einem Komma stehen und nach einem Komma MUSS ein Leerzeichen sein.
• Closure Argumente mit Vorgabewerten (default) MÜSSEN an das Ende der Argumentenliste.

Eine Closure Deklaration sieht wie nachfolgend aus. Beachten Sie die Plazierung von Klammern, Leerstellen und geschweiften Klammern. <PHP> $closureWithArgs = function ($arg1, $arg2) {

  // body

};

$closureWithArgsAndVars = function ($arg1, $arg2) use ($var1, $var2) {

  // body

}; </PHP>

• Argumenten- und Variablenlisten KÖNNEN über mehrere Zeilen gesplittet werden, wenn jede Unterzeile um eine Stufe eingerückt wird. Wenn so verfahren wird, MUSS das erste Element in die nächste Zeile und es DARF NICHT mehr als ein Argument oder Variable je Zeile angegeben werden.
• Wenn eine Argumenten- oder Variablenliste gesplittet wird, so MUSS die schließende Klammer und die öffnende geschweifte Klammer mit einer Leerstelle dazwischen in eine eigene Zeile.

Beispiele von Closures mit und ohne Argumentenliste und Variableliste die über mehrere Zeilen gesplittet sind. <PHP> $longArgs_noVars = function (

  $longArgument,
  $longerArgument,
  $muchLongerArgument

) {

 // body

};

$noArgs_longVars = function () use (

  $longVar1,
  $longerVar2,
  $muchLongerVar3

) {

 // body

};

$longArgs_longVars = function (

  $longArgument,
  $longerArgument,
  $muchLongerArgument

) use (

  $longVar1,
  $longerVar2,
  $muchLongerVar3

) {

 // body

};

$longArgs_shortVars = function (

  $longArgument,
  $longerArgument,
  $muchLongerArgument

) use ($var1) {

 // body

};

$shortArgs_longVars = function ($arg) use (

  $longVar1,
  $longerVar2,
  $muchLongerVar3

) {

 // body

}; </PHP> Beachten Sie, dass die Formatierungsregeln auch greifen, wenn ein Closure direkt in einem Funktions- oder Methodenaufruf als Argument eingesetzt ist. <PHP> $foo→bar(

  $arg1,
  function ($arg2) use ($var1) {
      // body
  },
  $arg3

); </PHP>