Try Rector Online | Rector - Automated Way to Instantly Upgrade and Refactor any PHP code

Run Rector on your code to see what it can do for you:

 <?php
 
-array_map(fn ($item) => reset($item), $data);
+array_map(reset(...), $data);

PHP snippet to change

<?php

array_map(fn ($item) => reset($item), $data);

Applied Rules:

ArrowFunctionDelegatingCallToFirstClassCallableRector

Not a change you expect?

Create an issue on GitHub
...or to speed up fix – add a test fixture

Config rector.php

<?php

use Rector\Config\RectorConfig;
use Rector\TypeDeclaration\Rector\Property\TypedPropertyFromAssignsRector;
use Rector\ValueObject\PhpVersion;

return RectorConfig::configure()
    ->withRules([
        Rector\CodingStyle\Rector\ArrowFunction\ArrowFunctionDelegatingCallToFirstClassCallableRector::class
    ]);

Rector version: b09565 - released at 2026-05-25 06:37