I'm a big fan of using collections in Laravel.

When you filter a collection in Laravel, you might have noticed that it keeps the original array indexes.

Imagine you have the following collection:

<?php
$collection = collect([
    1 => ['fruit' => 'Pear', 'price' => 100],
    2 => ['fruit' => 'Apple', 'price' => 300],
    3 => ['fruit' => 'Banana', 'price' => 200],
    4 => ['fruit' => 'Mango', 'price' => 500]
]);

When you filter the collection to retrieve all elements with a price higher than 200, you get:

<?php
$filtered = $collection->filter(fn ($item) => $item['price'] > 200)->all();
<?php
[
    2 => [
        "fruit" => "Apple",
        "price" => 300,
    ],
    4 => [
        "fruit" => "Mango",
        "price" => 500,
    ],
]

PS: I'm using the all method to get the result as a plain array.

Notice that the indexes are preserved. Sometimes, this can be annoying. There is however an easy fix by using the values method on the collection after the filtering.

<?php
$collection->filter(fn ($item) => $item['price'] > 200)->values()->all();
<?php
[
    [
        "fruit" => "Apple",
        "price" => 300,
    ],
    [
        "fruit" => "Mango",
        "price" => 500,
    ],
]