# RFC: enum SortDirection

- Status: Implemented (PHP 8.6)
- Authors: Tim Düsterhus, timwolla@php.net
- Date: 2026-03-02
- Version: 1.0
- Implementation: https://github.com/php/php-src/commit/32c1931f18109655bc074dd5cda3248b838de636
- Original: https://wiki.php.net/rfc/sort_direction_enum
- Page: https://externals.io/rfc/sort_direction_enum
- More for agents: search with https://externals.io/search.md?q={query} · RFCs at https://externals.io/rfc.md · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt

## Votes

### Implement the SortDirection enum as outlined in the RFC? (closed)

Yes: 22 · No: 2 · Abstain: 2

Voters: alcaeus (Yes), alexandredaubois (Yes), ashnazg (Yes), ayesh (Yes), beberlei (Yes), crell (Abstain), dams (Yes), daniels (Yes), derick (Yes), edorian (Yes), ericmann (Yes), galvao (Yes), girgias (Yes), iliaa (Yes), ilutov (Yes), malferov (No), marandall (Yes), mbeccati (Abstain), ocramius (Yes), petk (Yes), pmjones (Yes), pollita (No), ramsey (Yes), svpernova09 (Yes), theodorejb (Yes), timwolla (Yes)

## Discussions on the mailing list

- [\[RFC\] enum SortDirection](https://externals.io/message/130226.md) — started on 2026-03-02, 11 messages
- [\[VOTE\] enum SortDirection](https://externals.io/message/130395.md) — started on 2026-03-18, 4 messages

---

## Introduction

PHP’s standard library has no type-safe way to express sort direction. Today we use the integer constants `SORT_ASC` and `SORT_DESC` (which only work with `array_multisort()`), `SCANDIR_SORT_ASCENDING` and `SCANDIR_SORT_DESCENDING` (which only work with `scandir()`), bare `'ASC'` and `'DESC'` strings, `bool $ascending` flags, or entirely separate functions such as `sort()` vs `rsort()`.

Every major PHP framework and library ends up defining its own sort direction type. As an example, Doctrine introduced `\Doctrine\Common\Collections\Order` with `Ascending` and `Descending` cases as a replacement for its own now-deprecated string constants just two years ago.

This RFC proposes adding a single, always-available `SortDirection` enum to the global namespace:

```php
<?php
 
enum SortDirection {
    case Ascending;
    case Descending;
}
 
?>
```

This is intentionally small. It is a universally useful, generic type representing a common use case that PHP itself, frameworks, and other userland code can all converge on.

## Proposal

Add the following enum to ext/standard (in the global namespace):

```php
<?php
 
enum SortDirection {
    case Ascending;
    case Descending;
}
 
?>
```

The enum is an unbacked enum, because there is no single obvious canonical serialization format. It is meant to represent a generic concept that is useful across a wide range of applications (e.g. SQL queries, query-string parameters in APIs, …) and these applications can trivially map the enum to an appropriate scalar value using `match()` statements.

### Examples

SQL Query Builders:

```php
<?php
 
$query->orderBy('created_at', SortDirection::Descending);
 
?>
```

## Backward Incompatible Changes

The `SortDirection` class name in the global namespace is no longer available. A GitHub search for `language:PHP /(enum|class) SortDirection/` returns 178 results (both namespaced and unnamespaced).

Adding new symbols is not considered a BC break with regard to PHP’s policy, the name is the obvious choice and there is not a significant usage in the wild, making this an acceptable impact.

## Proposed PHP Version(s)

Next PHP 8.x (PHP 8.6).

## RFC Impact

### To the Ecosystem

APIs using the enum will benefit from improved type safety and discoverability.

It is also trivially polyfillable and supports forward compatibility when allowing the enum in addition to string / integer values by means of a union type. As such we expect quick adoption by the ecosystem.

### To Existing Extensions

Existing extensions may consider supporting the enum in addition to existing values in “sort direction” parameters (e.g. by means of a union type).

### To SAPIs

None.

## Open Issues

None.

## Future Scope

- Leveraging the enum in PHP’s standard library (e.g. for `scandir()`’s second parameter). This can happen without an RFC when it's just widening the type to an enum.

## Voting Choices

Primary Vote requiring a 2/3 majority to accept the RFC:

**Vote: Implement the SortDirection enum as outlined in the RFC?** — Yes: 22 · No: 2 · Abstain: 2 (closed)

## Patches and Tests

- <https://github.com/php/php-src/pull/21501>

## Implementation

- <https://github.com/php/php-src/commit/32c1931f18109655bc074dd5cda3248b838de636>

## References

- Mailing List Discussion: <https://news-web.php.net/php.internals/130226>
- Voting Thread: <https://news-web.php.net/php.internals/130395>

- PHP’s enum documentation using sort direction as a concept for the examples: <https://www.php.net/manual/en/language.enumerations.examples.php>
- Doctrine commit adding the `Order` enum: <https://github.com/doctrine/collections/commit/a288ea7d0af7763e05fc77fcc0c766f4b6f00fee>

## Rejected Features

None.

## Changelog

- 2026-03-02: Initial version