array_walk

Function • Return type changed in PHP 8.2

Apply a user supplied function to every member of an array.

PHP 5
PHP 7
PHP 8.0
Improved
PHP 8.1
PHP 8.2
Improved
PHP 8.3
PHP 8.4
PHP 8.5
PHP 8.6

array_walk Function synopsis

array_walk(
    object|array &$array,
    callable $callback,
    mixed $arg = <default>
  ): true

Parameters

$array

Passed by referenceTypeobject|array

The input array.

$callback

Typecallable

Typically, $callback takes on two parameters. The $array parameter's value being the first, and the key/index second.

$arg

OptionalTypemixedDefault value

If the optional $arg parameter is supplied, it will be passed as the third parameter to the $callback.

Note that the parameter $array is passed by reference, and contains additional/updated context data that may be useful.

Return value

Typetrue

Always returns true

Changes to the array_walk Function

PHP 8.2

  • Return type changed: bool to true
  array_walk(
      object|array &$array,
      callable $callback,
      mixed $arg = <default>
-   ): bool
+   ): true

PHP 8.0

  • Return type added: bool
  • Parameter name of parameter #1 changed: $input to $array
  • Parameter type added for parameter #1 ($array): object|array
  • Parameter name of parameter #2 changed: $funcname to $callback
  • Parameter type added for parameter #2 ($callback): callable
  • Parameter name of parameter #3 changed: $userdata to $arg
  • Parameter type added for parameter #3 ($arg): mixed
  • Parameter default value added for position #3 ($arg): <default>
  array_walk(
-     &$input,
+     object|array &$array,
-     $funcname,
+     callable $callback,
-     $userdata
+     mixed $arg = <default>
-   )
+   ): bool

array_walk Function Availability

PHP VersionAvailability
PHP 8.6Upcoming Release Yes
PHP 8.5Supported (Latest) Yes
PHP 8.4Supported Yes
PHP 8.3Security-Fixes Only Yes
PHP 8.2Security-Fixes Only Yes
PHP 8.1Unsupported Yes
PHP 8.0Unsupported Yes
PHP 7.4Unsupported Yes
PHP 7.3Unsupported Yes
PHP 7.2Unsupported Yes
PHP 7.1Unsupported Yes
PHP 7.0Unsupported Yes
PHP 5.6Unsupported Yes
PHP 5.5Unsupported Yes
PHP 5.4Unsupported Yes
PHP 5.3Unsupported Yes