The Arr::map() Helper

Overview

Arr::map() applies a callback to each value of a plain PHP array, returning a new array with the results. Unlike array_map(), it passes both the value and the key to your callback, and it preserves the original keys.

Usage

use Illuminate\Support\Arr;

$data = ['first' => 'taylor', 'last' => 'otwell'];

Arr::map($data, fn ($value, $key) => strtoupper($value));
// ['first' => 'TAYLOR', 'last' => 'OTWELL']

It recursively maps nested arrays too:

$config = [
    'database' => [
        'host' => 'localhost',
        'port' => '3306',
    ],
    'cache' => [
        'driver' => 'redis',
    ],
];

Arr::map($config, fn ($value) => is_string($value) ? strtoupper($value) : $value);
// [
//     'database' => ['host' => 'LOCALHOST', 'port' => '3306'],
//     'cache' => ['driver' => 'REDIS'],
// ]

Compared to array_map

// PHP's array_map — no key access, numeric re-indexing risk
array_map(fn ($v) => strtoupper($v), $data);

// Arr::map — key access, preserves keys, cleaner API
Arr::map($data, fn ($value, $key) => strtoupper($value));

When to Use

• Transforming config or settings arrays without creating a Collection
• Processing associative arrays where you need access to keys
• Working with nested data structures that need recursive mapping
• When collect()->map() feels like overkill for a simple array