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
 
 $arrayOfArrays = [['a'], ['a'], ['b']];
-$merged = array_unique(array_merge(...$arrayOfArrays));
+$merged = $arrayOfArrays
+    |> array_merge(...)
+    |> array_unique(...);
 
 var_dump($merged);

PHP snippet to change

<?php

$arrayOfArrays = [['a'], ['a'], ['b']];
$merged = array_unique(array_merge(...$arrayOfArrays));

var_dump($merged);

Applied Rules:

NestedFuncCallsToPipeOperatorRector

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\Php85\Rector\Expression\NestedFuncCallsToPipeOperatorRector;
use Rector\DeadCode\Rector\Expression\RemoveDeadStmtRector;
use Rector\ValueObject\PhpVersion;

return RectorConfig::configure()
    ->withRules([
        NestedFuncCallsToPipeOperatorRector::class,
    ])
    ->withPhpVersion(PhpVersion::PHP_85);

Rector version: d91338 - released at 2026-03-27 12:04