Collections

• Introduction
  • Creating Collections
  • Extending Collections
• Available Methods
• Higher Order Messages
• Lazy Collections
  • Introduction
  • Creating Lazy Collections
  • The Enumerable Contract
  • Lazy Collection Methods

Introduction

The Illuminate\Support\Collection class provides a fluent, convenient wrapper for working with arrays of data. For example, check out the following code. We'll use the collect helper to create a new collection instance from the array, run the strtoupper function on each element, and then remove all empty elements:

$collection = collect(['taylor', 'abigail', null])->map(function ($name) {
    return strtoupper($name);
})->reject(function ($name) {
    return empty($name);
});

As you can see, the Collection class allows you to chain its methods to perform fluent mapping and reducing of the underlying array. In general, collections are immutable, meaning every Collection method returns an entirely new Collection instance.

Creating Collections

As mentioned above, the collect helper returns a new Illuminate\Support\Collection instance for the given array. So, creating a collection is as simple as:

$collection = collect([1, 2, 3]);

Extending Collections

Collections are "macroable", which allows you to add additional methods to the Collection class at run time. The Illuminate\Support\Collection class' macro method accepts a closure that will be executed when your macro is called. The macro closure may access the collection's other methods via $this, just as if it were a real method of the collection class. For example, the following code adds a toUpper method to the Collection class:

use Illuminate\Support\Collection;
use Illuminate\Support\Str;
 
Collection::macro('toUpper', function () {
    return $this->map(function ($value) {
        return Str::upper($value);
    });
});
 
$collection = collect(['first', 'second']);
 
$upper = $collection->toUpper();
 
// ['FIRST', 'SECOND']

Typically, you should declare collection macros in the boot method of a service provider.

Macro Arguments

If necessary, you may define macros that accept additional arguments:

use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Lang;
 
Collection::macro('toLocale', function ($locale) {
    return $this->map(function ($value) use ($locale) {
        return Lang::get($value, [], $locale);
    });
});
 
$collection = collect(['first', 'second']);
 
$translated = $collection->toLocale('es');

Available Methods

For the majority of the remaining collection documentation, we'll discuss each method available on the Collection class. Remember, all of these methods may be chained to fluently manipulate the underlying array. Furthermore, almost every method returns a new Collection instance, allowing you to preserve the original copy of the collection when necessary:

Method Listing

all()

The all method returns the underlying array represented by the collection:

collect([1, 2, 3])->all();
 
// [1, 2, 3]

average()

Alias for the avg method.

avg()

The avg method returns the average value of a given key:

$average = collect([
    ['foo' => 10],
    ['foo' => 10],
    ['foo' => 20],
    ['foo' => 40]
])->avg('foo');
 
// 20
 
$average = collect([1, 1, 2, 4])->avg();
 
// 2

chunk()

The chunk method breaks the collection into multiple, smaller collections of a given size:

$collection = collect([1, 2, 3, 4, 5, 6, 7]);
 
$chunks = $collection->chunk(4);
 
$chunks->all();
 
// [[1, 2, 3, 4], [5, 6, 7]]

This method is especially useful in views when working with a grid system such as Bootstrap. For example, imagine you have a collection of Eloquent models you want to display in a grid:

@foreach ($products->chunk(3) as $chunk)
    <div class="row">
        @foreach ($chunk as $product)
            <div class="col-xs-4">{{ $product->name }}</div>
        @endforeach
    </div>
@endforeach

chunkWhile()

The chunkWhile method breaks the collection into multiple, smaller collections based on the evaluation of the given callback. The $chunk variable passed to the closure may be used to inspect the previous element:

$collection = collect(str_split('AABBCCCD'));
 
$chunks = $collection->chunkWhile(function ($value, $key, $chunk) {
    return $value === $chunk->last();
});
 
$chunks->all();
 
// [['A', 'A'], ['B', 'B'], ['C', 'C', 'C'], ['D']]

collapse()

The collapse method collapses a collection of arrays into a single, flat collection:

$collection = collect([
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9],
]);
 
$collapsed = $collection->collapse();
 
$collapsed->all();
 
// [1, 2, 3, 4, 5, 6, 7, 8, 9]

collect()

The collect method returns a new Collection instance with the items currently in the collection:

$collectionA = collect([1, 2, 3]);
 
$collectionB = $collectionA->collect();
 
$collectionB->all();
 
// [1, 2, 3]

The collect method is primarily useful for converting lazy collections into standard Collection instances:

$lazyCollection = LazyCollection::make(function () {
    yield 1;
    yield 2;
    yield 3;
});
 
$collection = $lazyCollection->collect();
 
get_class($collection);
 
// 'Illuminate\Support\Collection'
 
$collection->all();
 
// [1, 2, 3]

combine()

The combine method combines the values of the collection, as keys, with the values of another array or collection:

$collection = collect(['name', 'age']);
 
$combined = $collection->combine(['George', 29]);
 
$combined->all();
 
// ['name' => 'George', 'age' => 29]

concat()

The concat method appends the given array or collection's values onto the end of another collection:

$collection = collect(['John Doe']);
 
$concatenated = $collection->concat(['Jane Doe'])->concat(['name' => 'Johnny Doe']);
 
$concatenated->all();
 
// ['John Doe', 'Jane Doe', 'Johnny Doe']

contains()

The contains method determines whether the collection contains a given item. You may pass a closure to the contains method to determine if an element exists in the collection matching a given truth test:

$collection = collect([1, 2, 3, 4, 5]);
 
$collection->contains(function ($value, $key) {
    return $value > 5;
});
 
// false

Alternatively, you may pass a string to the contains method to determine whether the collection contains a given item value:

$collection = collect(['name' => 'Desk', 'price' => 100]);
 
$collection->contains('Desk');
 
// true
 
$collection->contains('New York');
 
// false

You may also pass a key / value pair to the contains method, which will determine if the given pair exists in the collection:

$collection = collect([
    ['product' => 'Desk', 'price' => 200],
    ['product' => 'Chair', 'price' => 100],
]);
 
$collection->contains('product', 'Bookcase');
 
// false

The contains method uses "loose" comparisons when checking item values, meaning a string with an integer value will be considered equal to an integer of the same value. Use the containsStrict method to filter using "strict" comparisons.

For the inverse of contains, see the doesntContain method.

containsStrict()

This method has the same signature as the contains method; however, all values are compared using "strict" comparisons.

count()

The count method returns the total number of items in the collection:

$collection = collect([1, 2, 3, 4]);
 
$collection->count();
 
// 4

countBy()

The countBy method counts the occurrences of values in the collection. By default, the method counts the occurrences of every element, allowing you to count certain "types" of elements in the collection:

$collection = collect([1, 2, 2, 2, 3]);
 
$counted = $collection->countBy();
 
$counted->all();
 
// [1 => 1, 2 => 3, 3 => 1]

You pass a closure to the countBy method to count all items by a custom value:

$collection = collect(['[email protected]', '[email protected]', '[email protected]']);
 
$counted = $collection->countBy(function ($email) {
    return substr(strrchr($email, "@"), 1);
});
 
$counted->all();
 
// ['gmail.com' => 2, 'yahoo.com' => 1]

crossJoin()

The crossJoin method cross joins the collection's values among the given arrays or collections, returning a Cartesian product with all possible permutations:

$collection = collect([1, 2]);
 
$matrix = $collection->crossJoin(['a', 'b']);
 
$matrix->all();
 
/*
    [
        [1, 'a'],
        [1, 'b'],
        [2, 'a'],
        [2, 'b'],
    ]
*/
 
$collection = collect([1, 2]);
 
$matrix = $collection->crossJoin(['a', 'b'], ['I', 'II']);
 
$matrix->all();
 
/*
    [
        [1, 'a', 'I'],
        [1, 'a', 'II'],
        [1, 'b', 'I'],
        [1, 'b', 'II'],
        [2, 'a', 'I'],
        [2, 'a', 'II'],
        [2, 'b', 'I'],
        [2, 'b', 'II'],
    ]
*/

dd()

The dd method dumps the collection's items and ends execution of the script:

$collection = collect(['John Doe', 'Jane Doe']);
 
$collection->dd();
 
/*
    Collection {
        #items: array:2 [
            0 => "John Doe"
            1 => "Jane Doe"
        ]
    }
*/

If you do not want to stop executing the script, use the dump method instead.

diff()

The diff method compares the collection against another collection or a plain PHP array based on its values. This method will return the values in the original collection that are not present in the given collection:

$collection = collect([1, 2, 3, 4, 5]);
 
$diff = $collection->diff([2, 4, 6, 8]);
 
$diff->all();
 
// [1, 3, 5]

diffAssoc()

The diffAssoc method compares the collection against another collection or a plain PHP array based on its keys and values. This method will return the key / value pairs in the original collection that are not present in the given collection:

$collection = collect([
    'color' => 'orange',
    'type' => 'fruit',
    'remain' => 6,
]);
 
$diff = $collection->diffAssoc([
    'color' => 'yellow',
    'type' => 'fruit',
    'remain' => 3,
    'used' => 6,
]);
 
$diff->all();
 
// ['color' => 'orange', 'remain' => 6]

diffKeys()

The diffKeys method compares the collection against another collection or a plain PHP array based on its keys. This method will return the key / value pairs in the original collection that are not present in the given collection:

$collection = collect([
    'one' => 10,
    'two' => 20,
    'three' => 30,
    'four' => 40,
    'five' => 50,
]);
 
$diff = $collection->diffKeys([
    'two' => 2,
    'four' => 4,
    'six' => 6,
    'eight' => 8,
]);
 
$diff->all();
 
// ['one' => 10, 'three' => 30, 'five' => 50]

doesntContain()

The doesntContain method determines whether the collection does not contain a given item. You may pass a closure to the doesntContain method to determine if an element does not exist in the collection matching a given truth test:

$collection = collect([1, 2, 3, 4, 5]);
 
$collection->doesntContain(function ($value, $key) {
    return $value < 5;
});
 
// false

Alternatively, you may pass a string to the doesntContain method to determine whether the collection does not contain a given item value:

$collection = collect(['name' => 'Desk', 'price' => 100]);
 
$collection->doesntContain('Table');
 
// true
 
$collection->doesntContain('Desk');
 
// false

You may also pass a key / value pair to the doesntContain method, which will determine if the given pair does not exist in the collection:

$collection = collect([
    ['product' => 'Desk', 'price' => 200],
    ['product' => 'Chair', 'price' => 100],
]);
 
$collection->doesntContain('product', 'Bookcase');
 
// true

The doesntContain method uses "loose" comparisons when checking item values, meaning a string with an integer value will be considered equal to an integer of the same value.

dump()

The dump method dumps the collection's items:

$collection = collect(['John Doe', 'Jane Doe']);
 
$collection->dump();
 
/*
    Collection {
        #items: array:2 [
            0 => "John Doe"
            1 => "Jane Doe"
        ]
    }
*/

If you want to stop executing the script after dumping the collection, use the dd method instead.

duplicates()

The duplicates method retrieves and returns duplicate values from the collection:

$collection = collect(['a', 'b', 'a', 'c', 'b']);
 
$collection->duplicates();
 
// [2 => 'a', 4 => 'b']

If the collection contains arrays or objects, you can pass the key of the attributes that you wish to check for duplicate values:

$employees = collect([
    ['email' => '[email protected]', 'position' => 'Developer'],
    ['email' => '[email protected]', 'position' => 'Designer'],
    ['email' => '[email protected]', 'position' => 'Developer'],
]);
 
$employees->duplicates('position');
 
// [2 => 'Developer']

duplicatesStrict()

This method has the same signature as the duplicates method; however, all values are compared using "strict" comparisons.

each()

The each method iterates over the items in the collection and passes each item to a closure:

$collection->each(function ($item, $key) {
    //
});

If you would like to stop iterating through the items, you may return false from your closure:

$collection->each(function ($item, $key) {
    if (/* condition */) {
        return false;
    }
});

eachSpread()

The eachSpread method iterates over the collection's items, passing each nested item value into the given callback:

$collection = collect([['John Doe', 35], ['Jane Doe', 33]]);
 
$collection->eachSpread(function ($name, $age) {
    //
});

You may stop iterating through the items by returning false from the callback:

$collection->eachSpread(function ($name, $age) {
    return false;
});

every()

The every method may be used to verify that all elements of a collection pass a given truth test:

collect([1, 2, 3, 4])->every(function ($value, $key) {
    return $value > 2;
});
 
// false

If the collection is empty, the every method will return true:

$collection = collect([]);
 
$collection->every(function ($value, $key) {
    return $value > 2;
});
 
// true

except()

The except method returns all items in the collection except for those with the specified keys:

$collection = collect(['product_id' => 1, 'price' => 100, 'discount' => false]);
 
$filtered = $collection->except(['price', 'discount']);
 
$filtered->all();
 
// ['product_id' => 1]

For the inverse of except, see the only method.

filter()

The filter method filters the collection using the given callback, keeping only those items that pass a given truth test:

$collection = collect([1, 2, 3, 4]);
 
$filtered = $collection->filter(function ($value, $key) {
    return $value > 2;
});
 
$filtered->all();
 
// [3, 4]

If no callback is supplied, all entries of the collection that are equivalent to false will be removed:

$collection = collect([1, 2, 3, null, false, '', 0, []]);
 
$collection->filter()->all();
 
// [1, 2, 3]

For the inverse of filter, see the reject method.

first()

The first method returns the first element in the collection that passes a given truth test:

collect([1, 2, 3, 4])->first(function ($value, $key) {
    return $value > 2;
});
 
// 3

You may also call the first method with no arguments to get the first element in the collection. If the collection is empty, null is returned:

collect([1, 2, 3, 4])->first();
 
// 1

firstWhere()

The firstWhere method returns the first element in the collection with the given key / value pair:

$collection = collect([
    ['name' => 'Regena', 'age' => null],
    ['name' => 'Linda', 'age' => 14],
    ['name' => 'Diego', 'age' => 23],
    ['name' => 'Linda', 'age' => 84],
]);
 
$collection->firstWhere('name', 'Linda');
 
// ['name' => 'Linda', 'age' => 14]

You may also call the firstWhere method with a comparison operator:

$collection->firstWhere('age', '>=', 18);
 
// ['name' => 'Diego', 'age' => 23]

Like the where method, you may pass one argument to the firstWhere method. In this scenario, the firstWhere method will return the first item where the given item key's value is "truthy":

$collection->firstWhere('age');
 
// ['name' => 'Linda', 'age' => 14]

flatMap()

The flatMap method iterates through the collection and passes each value to the given closure. The closure is free to modify the item and return it, thus forming a new collection of modified items. Then, the array is flattened by one level:

$collection = collect([
    ['name' => 'Sally'],
    ['school' => 'Arkansas'],
    ['age' => 28]
]);
 
$flattened = $collection->flatMap(function ($values) {
    return array_map('strtoupper', $values);
});
 
$flattened->all();
 
// ['name' => 'SALLY', 'school' => 'ARKANSAS', 'age' => '28'];

flatten()

The flatten method flattens a multi-dimensional collection into a single dimension:

$collection = collect([
    'name' => 'taylor',
    'languages' => [
        'php', 'javascript'
    ]
]);
 
$flattened = $collection->flatten();
 
$flattened->all();
 
// ['taylor', 'php', 'javascript'];

If necessary, you may pass the flatten method a "depth" argument:

$collection = collect([
    'Apple' => [
        [
            'name' => 'iPhone 6S',
            'brand' => 'Apple'
        ],
    ],
    'Samsung' => [
        [
            'name' => 'Galaxy S7',
            'brand' => 'Samsung'
        ],
    ],
]);
 
$products = $collection->flatten(1);
 
$products->values()->all();
 
/*
    [
        ['name' => 'iPhone 6S', 'brand' => 'Apple'],
        ['name' => 'Galaxy S7', 'brand' => 'Samsung'],
    ]
*/

In this example, calling flatten without providing the depth would have also flattened the nested arrays, resulting in ['iPhone 6S', 'Apple', 'Galaxy S7', 'Samsung']. Providing a depth allows you to specify the number of levels nested arrays will be flattened.

flip()

The flip method swaps the collection's keys with their corresponding values:

$collection = collect(['name' => 'taylor', 'framework' => 'laravel']);
 
$flipped = $collection->flip();
 
$flipped->all();
 
// ['taylor' => 'name', 'laravel' => 'framework']

forget()

The forget method removes an item from the collection by its key:

$collection = collect(['name' => 'taylor', 'framework' => 'laravel']);
 
$collection->forget('name');
 
$collection->all();
 
// ['framework' => 'laravel']

forPage()

The forPage method returns a new collection containing the items that would be present on a given page number. The method accepts the page number as its first argument and the number of items to show per page as its second argument:

$collection = collect([1, 2, 3, 4, 5, 6, 7, 8, 9]);
 
$chunk = $collection->forPage(2, 3);
 
$chunk->all();
 
// [4, 5, 6]

get()

The get method returns the item at a given key. If the key does not exist, null is returned:

$collection = collect(['name' => 'taylor', 'framework' => 'laravel']);
 
$value = $collection->get('name');
 
// taylor

You may optionally pass a default value as the second argument:

$collection = collect(['name' => 'taylor', 'framework' => 'laravel']);
 
$value = $collection->get('age', 34);
 
// 34

You may even pass a callback as the method's default value. The result of the callback will be returned if the specified key does not exist:

$collection->get('email', function () {
    return '[email protected]';
});
 
// [email protected]

groupBy()

The groupBy method groups the collection's items by a given key:

$collection = collect([
    ['account_id' => 'account-x10', 'product' => 'Chair'],
    ['account_id' => 'account-x10', 'product' => 'Bookcase'],
    ['account_id' => 'account-x11', 'product' => 'Desk'],
]);
 
$grouped = $collection->groupBy('account_id');
 
$grouped->all();
 
/*
    [
        'account-x10' => [
            ['account_id' => 'account-x10', 'product' => 'Chair'],
            ['account_id' => 'account-x10', 'product' => 'Bookcase'],
        ],
        'account-x11' => [
            ['account_id' => 'account-x11', 'product' => 'Desk'],
        ],
    ]
*/

Instead of passing a string key, you may pass a callback. The callback should return the value you wish to key the group by:

$grouped = $collection->groupBy(function ($item, $key) {
    return substr($item['account_id'], -3);
});
 
$grouped->all();
 
/*
    [
        'x10' => [
            ['account_id' => 'account-x10', 'product' => 'Chair'],
            ['account_id' => 'account-x10', 'product' => 'Bookcase'],
        ],
        'x11' => [
            ['account_id' => 'account-x11', 'product' => 'Desk'],
        ],
    ]
*/

Multiple grouping criteria may be passed as an array. Each array element will be applied to the corresponding level within a multi-dimensional array:

$data = new Collection([
    10 => ['user' => 1, 'skill' => 1, 'roles' => ['Role_1', 'Role_3']],
    20 => ['user' => 2, 'skill' => 1, 'roles' => ['Role_1', 'Role_2']],
    30 => ['user' => 3, 'skill' => 2, 'roles' => ['Role_1']],
    40 => ['user' => 4, 'skill' => 2, 'roles' => ['Role_2']],
]);
 
$result = $data->groupBy(['skill', function ($item) {
    return $item['roles'];
}], $preserveKeys = true);
 
/*
[
    1 => [
        'Role_1' => [
            10 => ['user' => 1, 'skill' => 1, 'roles' => ['Role_1', 'Role_3']],
            20 => ['user' => 2, 'skill' => 1, 'roles' => ['Role_1', 'Role_2']],
        ],
        'Role_2' => [
            20 => ['user' => 2, 'skill' => 1, 'roles' => ['Role_1', 'Role_2']],
        ],
        'Role_3' => [
            10 => ['user' => 1, 'skill' => 1, 'roles' => ['Role_1', 'Role_3']],
        ],
    ],
    2 => [
        'Role_1' => [
            30 => ['user' => 3, 'skill' => 2, 'roles' => ['Role_1']],
        ],
        'Role_2' => [
            40 => ['user' => 4, 'skill' => 2, 'roles' => ['Role_2']],
        ],
    ],
];
*/

has()

The has method determines if a given key exists in the collection:

$collection = collect(['account_id' => 1, 'product' => 'Desk', 'amount' => 5]);
 
$collection->has('product');
 
// true
 
$collection->has(['product', 'amount']);
 
// true
 
$collection->has(['amount', 'price']);
 
// false

implode()

The implode method joins items in a collection. Its arguments depend on the type of items in the collection. If the collection contains arrays or objects, you should pass the key of the attributes you wish to join, and the "glue" string you wish to place between the values:

$collection = collect([
    ['account_id' => 1, 'product' => 'Desk'],
    ['account_id' => 2, 'product' => 'Chair'],
]);
 
$collection->implode('product', ', ');
 
// Desk, Chair

If the collection contains simple strings or numeric values, you should pass the "glue" as the only argument to the method:

collect([1, 2, 3, 4, 5])->implode('-');
 
// '1-2-3-4-5'

intersect()

The intersect method removes any values from the original collection that are not present in the given array or collection. The resulting collection will preserve the original collection's keys:

$collection = collect(['Desk', 'Sofa', 'Chair']);
 
$intersect = $collection->intersect(['Desk', 'Chair', 'Bookcase']);
 
$intersect->all();
 
// [0 => 'Desk', 2 => 'Chair']

intersectByKeys()

The intersectByKeys method removes any keys and their corresponding values from the original collection that are not present in the given array or collection:

$collection = collect([
    'serial' => 'UX301', 'type' => 'screen', 'year' => 2009,
]);
 
$intersect = $collection->intersectByKeys([
    'reference' => 'UX404', 'type' => 'tab', 'year' => 2011,
]);
 
$intersect->all();
 
// ['type' => 'screen', 'year' => 2009]

isEmpty()

The isEmpty method returns true if the collection is empty; otherwise, false is returned:

collect([])->isEmpty();
 
// true

isNotEmpty()

The isNotEmpty method returns true if the collection is not empty; otherwise, false is returned:

collect([])->isNotEmpty();
 
// false

join()

The join method joins the collection's values with a string. Using this method's second argument, you may also specify how the final element should be appended to the string:

collect(['a', 'b', 'c'])->join(', '); // 'a, b, c'
collect(['a', 'b', 'c'])->join(', ', ', and '); // 'a, b, and c'
collect(['a', 'b'])->join(', ', ' and '); // 'a and b'
collect(['a'])->join(', ', ' and '); // 'a'
collect([])->join(', ', ' and '); // ''

keyBy()

The keyBy method keys the collection by the given key. If multiple items have the same key, only the last one will appear in the new collection:

$collection = collect([
    ['product_id' => 'prod-100', 'name' => 'Desk'],
    ['product_id' => 'prod-200', 'name' => 'Chair'],
]);
 
$keyed = $collection->keyBy('product_id');
 
$keyed->all();
 
/*
    [
        'prod-100' => ['product_id' => 'prod-100', 'name' => 'Desk'],
        'prod-200' => ['product_id' => 'prod-200', 'name' => 'Chair'],
    ]
*/

You may also pass a callback to the method. The callback should return the value to key the collection by:

$keyed = $collection->keyBy(function ($item) {
    return strtoupper($item['product_id']);
});
 
$keyed->all();
 
/*
    [
        'PROD-100' => ['product_id' => 'prod-100', 'name' => 'Desk'],
        'PROD-200' => ['product_id' => 'prod-200', 'name' => 'Chair'],
    ]
*/

keys()

The keys method returns all of the collection's keys:

$collection = collect([
    'prod-100' => ['product_id' => 'prod-100', 'name' => 'Desk'],
    'prod-200' => ['product_id' => 'prod-200', 'name' => 'Chair'],
]);
 
$keys = $collection->keys();
 
$keys->all();
 
// ['prod-100', 'prod-200']

last()

The last method returns the last element in the collection that passes a given truth test:

collect([1, 2, 3, 4])->last(function ($value, $key) {
    return $value < 3;
});
 
// 2

You may also call the last method with no arguments to get the last element in the collection. If the collection is empty, null is returned:

collect([1, 2, 3, 4])->last();
 
// 4

macro()

The static macro method allows you to add methods to the Collection class at run time. Refer to the documentation on extending collections for more information.

make()

The static make method creates a new collection instance. See the Creating Collections section.

map()

The map method iterates through the collection and passes each value to the given callback. The callback is free to modify the item and return it, thus forming a new collection of modified items:

$collection = collect([1, 2, 3, 4, 5]);
 
$multiplied = $collection->map(function ($item, $key) {
    return $item * 2;
});
 
$multiplied->all();
 
// [2, 4, 6, 8, 10]

mapInto()

The mapInto() method iterates over the collection, creating a new instance of the given class by passing the value into the constructor:

class Currency
{
    /**
     * Create a new currency instance.
     *
     * @param  string  $code
     * @return void
     */
    function __construct(string $code)
    {
        $this->code = $code;
    }
}
 
$collection = collect(['USD', 'EUR', 'GBP']);
 
$currencies = $collection->mapInto(Currency::class);
 
$currencies->all();
 
// [Currency('USD'), Currency('EUR'), Currency('GBP')]

mapSpread()

The mapSpread method iterates over the collection's items, passing each nested item value into the given closure. The closure is free to modify the item and return it, thus forming a new collection of modified items:

$collection = collect([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
 
$chunks = $collection->chunk(2);
 
$sequence = $chunks->mapSpread(function ($even, $odd) {
    return $even + $odd;
});
 
$sequence->all();
 
// [1, 5, 9, 13, 17]

mapToGroups()

The mapToGroups method groups the collection's items by the given closure. The closure should return an associative array containing a single key / value pair, thus forming a new collection of grouped values:

$collection = collect([
    [
        'name' => 'John Doe',
        'department' => 'Sales',
    ],
    [
        'name' => 'Jane Doe',
        'department' => 'Sales',
    ],
    [
        'name' => 'Johnny Doe',
        'department' => 'Marketing',
    ]
]);
 
$grouped = $collection->mapToGroups(function ($item, $key) {
    return [$item['department'] => $item['name']];
});
 
$grouped->all();
 
/*
    [
        'Sales' => ['John Doe', 'Jane Doe'],
        'Marketing' => ['Johnny Doe'],
    ]
*/
 
$grouped->get('Sales')->all();
 
// ['John Doe', 'Jane Doe']

mapWithKeys()

The mapWithKeys method iterates through the collection and passes each value to the given callback. The callback should return an associative array containing a single key / value pair:

$collection = collect([
    [
        'name' => 'John',
        'department' => 'Sales',
        'email' => '[email protected]',
    ],
    [
        'name' => 'Jane',
        'department' => 'Marketing',
        'email' => '[email protected]',
    ]
]);
 
$keyed = $collection->mapWithKeys(function ($item, $key) {
    return [$item['email'] => $item['name']];
});
 
$keyed->all();
 
/*
    [
        '[email protected]' => 'John',
        '[email protected]' => 'Jane',
    ]
*/

max()

The max method returns the maximum value of a given key:

$max = collect([
    ['foo' => 10],
    ['foo' => 20]
])->max('foo');
 
// 20
 
$max = collect([1, 2, 3, 4, 5])->max();
 
// 5

median()

The median method returns the median value of a given key:

$median = collect([
    ['foo' => 10],
    ['foo' => 10],
    ['foo' => 20],
    ['foo' => 40]
])->median('foo');
 
// 15
 
$median = collect([1, 1, 2, 4])->median();
 
// 1.5

merge()

The merge method merges the given array or collection with the original collection. If a string key in the given items matches a string key in the original collection, the given items's value will overwrite the value in the original collection:

$collection = collect(['product_id' => 1, 'price' => 100]);
 
$merged = $collection->merge(['price' => 200, 'discount' => false]);
 
$merged->all();
 
// ['product_id' => 1, 'price' => 200, 'discount' => false]

If the given items's keys are numeric, the values will be appended to the end of the collection:

$collection = collect(['Desk', 'Chair']);
 
$merged = $collection->merge(['Bookcase', 'Door']);
 
$merged->all();
 
// ['Desk', 'Chair', 'Bookcase', 'Door']

mergeRecursive()

The mergeRecursive method merges the given array or collection recursively with the original collection. If a string key in the given items matches a string key in the original collection, then the values for these keys are merged together into an array, and this is done recursively:

$collection = collect(['product_id' => 1, 'price' => 100]);
 
$merged = $collection->mergeRecursive([
    'product_id' => 2,
    'price' => 200,
    'discount' => false
]);
 
$merged->all();
 
// ['product_id' => [1, 2], 'price' => [100, 200], 'discount' => false]

min()

The min method returns the minimum value of a given key:

$min = collect([['foo' => 10], ['foo' => 20]])->min('foo');
 
// 10
 
$min = collect([1, 2, 3, 4, 5])->min();
 
// 1

mode()

The mode method returns the mode value of a given key:

$mode = collect([
    ['foo' => 10],
    ['foo' => 10],
    ['foo' => 20],
    ['foo' => 40]
])->mode('foo');
 
// [10]
 
$mode = collect([1, 1, 2, 4])->mode();
 
// [1]
 
$mode = collect([1, 1, 2, 2])->mode();
 
// [1, 2]

nth()

The nth method creates a new collection consisting of every n-th element:

$collection = collect(['a', 'b', 'c', 'd', 'e', 'f']);
 
$collection->nth(4);
 
// ['a', 'e']

You may optionally pass a starting offset as the second argument:

$collection->nth(4, 1);
 
// ['b', 'f']

only()

The only method returns the items in the collection with the specified keys:

$collection = collect([
    'product_id' => 1,
    'name' => 'Desk',
    'price' => 100,
    'discount' => false
]);
 
$filtered = $collection->only(['product_id', 'name']);
 
$filtered->all();
 
// ['product_id' => 1, 'name' => 'Desk']

For the inverse of only, see the except method.

pad()

The pad method will fill the array with the given value until the array reaches the specified size. This method behaves like the array_pad PHP function.

To pad to the left, you should specify a negative size. No padding will take place if the absolute value of the given size is less than or equal to the length of the array:

$collection = collect(['A', 'B', 'C']);
 
$filtered = $collection->pad(5, 0);
 
$filtered->all();
 
// ['A', 'B', 'C', 0, 0]
 
$filtered = $collection->pad(-5, 0);
 
$filtered->all();
 
// [0, 0, 'A', 'B', 'C']

partition()

The partition method may be combined with PHP array destructuring to separate elements that pass a given truth test from those that do not:

$collection = collect([1, 2, 3, 4, 5, 6]);
 
[$underThree, $equalOrAboveThree] = $collection->partition(function ($i) {
    return $i < 3;
});
 
$underThree->all();
 
// [1, 2]
 
$equalOrAboveThree->all();
 
// [3, 4, 5, 6]

pipe()

The pipe method passes the collection to the given closure and returns the result of the executed closure:

$collection = collect([1, 2, 3]);
 
$piped = $collection->pipe(function ($collection) {
    return $collection->sum();
});
 
// 6

pipeInto()

The pipeInto method creates a new instance of the given class and passes the collection into the constructor:

class ResourceCollection
{
    /**
     * The Collection instance.
     */
    public $collection;
 
    /**
     * Create a new ResourceCollection instance.
     *
     * @param  Collection  $collection
     * @return void
     */
    public function __construct(Collection $collection)
    {
        $this->collection = $collection;
    }
}
 
$collection = collect([1, 2, 3]);
 
$resource = $collection->pipeInto(ResourceCollection::class);
 
$resource->collection->all();
 
// [1, 2, 3]

pipeThrough()

The pipeThrough method passes the collection to the given array of closures and returns the result of the executed closures:

$collection = collect([1, 2, 3]);
 
$result = $collection->pipeThrough([
    function ($collection) {
        return $collection->merge([4, 5]);
    },
    function ($collection) {
        return $collection->sum();
    },
]);
 
// 15

pluck()

The pluck method retrieves all of the values for a given key:

$collection = collect([
    ['product_id' => 'prod-100', 'name' => 'Desk'],
    ['product_id' => 'prod-200', 'name' => 'Chair'],
]);
 
$plucked = $collection->pluck('name');
 
$plucked->all();
 
// ['Desk', 'Chair']

You may also specify how you wish the resulting collection to be keyed:

$plucked = $collection->pluck('name', 'product_id');
 
$plucked->all();
 
// ['prod-100' => 'Desk', 'prod-200' => 'Chair']

The pluck method also supports retrieving nested values using "dot" notation:

$collection = collect([
    [
        'speakers' => [
            'first_day' => ['Rosa', 'Judith'],
            'second_day' => ['Angela', 'Kathleen'],
        ],
    ],
]);
 
$plucked = $collection->pluck('speakers.first_day');
 
$plucked->all();
 
// ['Rosa', 'Judith']

If duplicate keys exist, the last matching element will be inserted into the plucked collection:

$collection = collect([
    ['brand' => 'Tesla',  'color' => 'red'],
    ['brand' => 'Pagani', 'color' => 'white'],
    ['brand' => 'Tesla',  'color' => 'black'],
    ['brand' => 'Pagani', 'color' => 'orange'],
]);
 
$plucked = $collection->pluck('color', 'brand');
 
$plucked->all();
 
// ['Tesla' => 'black', 'Pagani' => 'orange']

pop()

The pop method removes and returns the last item from the collection:

$collection = collect([1, 2, 3, 4, 5]);
 
$collection->pop();
 
// 5
 
$collection->all();
 
// [1, 2, 3, 4]

You may pass an integer to the pop method to remove and return multiple items from the end of a collection:

$collection = collect([1, 2, 3, 4, 5]);
 
$collection->pop(3);
 
// collect([5, 4, 3])
 
$collection->all();
 
// [1, 2]

prepend()

The prepend method adds an item to the beginning of the collection:

$collection = collect([1, 2, 3, 4, 5]);
 
$collection->prepend(0);
 
$collection->all();
 
// [0, 1, 2, 3, 4, 5]

You may also pass a second argument to specify the key of the prepended item:

$collection = collect(['one' => 1, 'two' => 2]);
 
$collection->prepend(0, 'zero');
 
$collection->all();
 
// ['zero' => 0, 'one' => 1, 'two' => 2]

pull()

The pull method removes and returns an item from the collection by its key:

$collection = collect(['product_id' => 'prod-100', 'name' => 'Desk']);
 
$collection->pull('name');
 
// 'Desk'
 
$collection->all();
 
// ['product_id' => 'prod-100']

push()

The push method appends an item to the end of the collection:

$collection = collect([1, 2, 3, 4]);
 
$collection->push(5);
 
$collection->all();
 
// [1, 2, 3, 4, 5]

put()

The put method sets the given key and value in the collection:

$collection = collect(['product_id' => 1, 'name' => 'Desk']);
 
$collection->put('price', 100);
 
$collection->all();
 
// ['product_id' => 1, 'name' => 'Desk', 'price' => 100]

random()

The random method returns a random item from the collection:

$collection = collect([1, 2, 3, 4, 5]);
 
$collection->random();
 
// 4 - (retrieved randomly)

You may pass an integer to random to specify how many items you would like to randomly retrieve. A collection of items is always returned when explicitly passing the number of items you wish to receive:

$random = $collection->random(3);
 
$random->all();
 
// [2, 4, 5] - (retrieved randomly)

If the collection instance has fewer items than requested, the random method will throw an InvalidArgumentException.

range()

The range method returns a collection containing integers between the specified range:

$collection = collect()->range(3, 6);
 
$collection->all();
 
// [3, 4, 5, 6]

reduce()

The reduce method reduces the collection to a single value, passing the result of each iteration into the subsequent iteration:

$collection = collect([1, 2, 3]);
 
$total = $collection->reduce(function ($carry, $item) {
    return $carry + $item;
});
 
// 6

The value for $carry on the first iteration is null; however, you may specify its initial value by passing a second argument to reduce:

$collection->reduce(function ($carry, $item) {
    return $carry + $item;
}, 4);
 
// 10

The reduce method also passes array keys in associative collections to the given callback:

$collection = collect([
    'usd' => 1400,
    'gbp' => 1200,
    'eur' => 1000,
]);
 
$ratio = [
    'usd' => 1,
    'gbp' => 1.37,
    'eur' => 1.22,
];
 
$collection->reduce(function ($carry, $value, $key) use ($ratio) {
    return $carry + ($value * $ratio[$key]);
});
 
// 4264

reduceSpread()

The reduceSpread method reduces the collection to an array of values, passing the results of each iteration into the subsequent iteration. This method is similar to the reduce method; however, it can accept multiple initial values:

[$creditsRemaining, $batch] = Image::where('status', 'unprocessed')
        ->get()
        ->reduceSpread(function ($creditsRemaining, $batch, $image) {
            if ($creditsRemaining >= $image->creditsRequired()) {
                $batch->push($image);
 
                $creditsRemaining -= $image->creditsRequired();
            }
 
            return [$creditsRemaining, $batch];
        }, $creditsAvailable, collect());

reject()

The reject method filters the collection using the given closure. The closure should return true if the item should be removed from the resulting collection:

$collection = collect([1, 2, 3, 4]);
 
$filtered = $collection->reject(function ($value, $key) {
    return $value > 2;
});
 
$filtered->all();
 
// [1, 2]

For the inverse of the reject method, see the filter method.

replace()

The replace method behaves similarly to merge; however, in addition to overwriting matching items that have string keys, the replace method will also overwrite items in the collection that have matching numeric keys:

$collection = collect(['Taylor', 'Abigail', 'James']);
 
$replaced = $collection->replace([1 => 'Victoria', 3 => 'Finn']);
 
$replaced->all();
 
// ['Taylor', 'Victoria', 'James', 'Finn']

replaceRecursive()

This method works like replace, but it will recur into arrays and apply the same replacement process to the inner values:

$collection = collect([
    'Taylor',
    'Abigail',
    [
        'James',
        'Victoria',
        'Finn'
    ]
]);
 
$replaced = $collection->replaceRecursive([
    'Charlie',
    2 => [1 => 'King']
]);
 
$replaced->all();
 
// ['Charlie', 'Abigail', ['James', 'King', 'Finn']]