How to access the nth item in a Laravel collection?

Question

I guess I am breaking all the rules by deliberately making a duplicate question...

The other question has an accepted answer. It obviously solved the askers problem, but it did not answer the title question.

Let's start from the beginning - the first() method is implemented approximately like this:

foreach ($collection as $item)
    return $item;

It is obviously more robust than taking $collection[0] or using other suggested methods.

There might be no item with index 0 or index 15 even if there are 20 items in the collection. To illustrate the problem, let's take this collection out of the docs:

$collection = collect([
    ['product_id' => 'prod-100', 'name' => 'desk'],
    ['product_id' => 'prod-200', 'name' => 'chair'],
]);

$keyed = $collection->keyBy('product_id');

Now, do we have any reliable (and preferably concise) way to access nth item of $keyed?

My own suggestion would be to do:

$nth = $keyed->take($n)->last();

But this will give the wrong item ($keyed->last()) whenever $n > $keyed->count(). How can we get the nth item if it exists and null if it doesn't just like first() behaves?

Edit

To clarify, let's consider this collection:

$col = collect([
    2 => 'a',
    5 => 'b',
    6 => 'c',
    7 => 'd']);

First item is $col->first(). How to get the second?

$col->nth(3) should return 'c' (or 'c' if 0-based, but that would be inconsistent with first()). $col[3] wouldn't work, it would just return an error.

$col->nth(7) should return null because there is no seventh item, there are only four of them. $col[7] wouldn't work, it would just return 'd'.

You could rephrase the question as "How to get nth item in the foreach order?" if it's more clear for some.

Psoriasis

As in the answer to the question you mentioned, you can do $collection->get($nth, 'some default value') – Savina

@tam It uses the keys just like [$nth] does... – Strickman

Answer 1

I guess faster and more memory-efficient way is to use slice() method:

$collection->slice($n, 1);

Babble

This seems nice, but I am not sure about the behaviour if $n > $collection->count(). It appears that slice() uses PHPs array_slice() and I can't find info on behaviour if $n exceeds the size of array. Maybe it's unspecified and unreliable :| – Strickman

It will just return an empty collection. You even can do easy check with ->isEmpty() or empty($result). – Babble

Mkay, then $collection->slice($n, 1)->fiirst() will return nth item if it exists and null otherwise. Seems great :) – Strickman

Two issues with this answer to consider: a) this returns a collection of one, so $collection->slice($n, 1)->first() must be used; b) $n is zero indexed, so will return the $n+1 element from the collection. So for this example use: $collection->slice($n-1, 1)->first() – Lilybel

Answer 2

You can try it using values() function as:

$collection->values()->get($n);

Luau

This seems the best solution so far, can't think of an example where it fails :) – Strickman

It's working solution but it will duplicate whole collection and may kill an app, if collection is big by itself (collection of articles with relations or something similar). – Babble

Answer 3

Based on Alexey's answer, you can create a macro in AppServiceProvider (add it inside register method):

use Illuminate\Support\Collection;

Collection::macro('getNth', function ($n) {
   return $this->slice($n, 1)->first();
});

and then, you can use this throughout your application:

$collection = ['apple', 'orange'];

$collection->getNth(0) // returns 'apple'
$collection->getNth(1) // returns 'orange'
$collection->getNth(2) // returns null
$collection->getNth(3) // returns null

Vernita

Answer 4

you may use offsetGet since Collection class implements ArrayAccess

$lines->offsetGet($nth);

Guanine

Answer 5

Maybe not the best option, but, you can get item from array inside collection

$collection->all()[0] 

Enlarger