usort

Function • Return type changed in PHP 8.2

Sort an array by values using a user-defined comparison function.

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

usort Function synopsis

usort(array &$array, callable $callback): true

Parameters

$array

Passed by referenceTypearray

The input array.

$callback

Typecallable

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 usort Function

PHP 8.2

  • Return type changed: bool to true
- usort(array &$array, callable $callback): bool
+ usort(array &$array, callable $callback): true

PHP 8.0

  • Return type added: bool
  • Parameter name of parameter #1 changed: $arg to $array
  • Parameter type added for parameter #1 ($array): array
  • Parameter name of parameter #2 changed: $cmp_function to $callback
  • Parameter type added for parameter #2 ($callback): callable
- usort(&$arg, $cmp_function)
+ usort(array &$array, callable $callback): bool

usort 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