Laravel collections are one of the most powerful tools in the framework. They extend the Illuminate\Support\Collection class and provide a smooth interface to manipulate arrays and objects in an expressive way.
Creating Collections
You can create a collection from an array using the collect() method:
$collection = collect([1, 2, 3, 4, 5]);
Key Collection Methods
Below, we'll dive into some of the most useful and powerful methods.
map() - Transforming Values
The map() method lets you apply a function to each item in the collection.
$doubled = collect([1, 2, 3])->map(fn($num) => $num * 2);
// [2, 4, 6]
filter() - Filtering Values
Filters the collection items based on a condition.
$evenNumbers = collect([1, 2, 3, 4, 5])->filter(fn($num) => $num % 2 === 0);
// [2, 4]
reduce() - Reducing to a Single value
Useful for collapsing the collection into a single accumulated value.
$sum = collect([1, 2, 3, 4])->reduce(fn($carry, $num) => $carry + $num, 0);
// 10
pluck() - Extracting Values from a Field
The pluck() method allows you to extract values from a specific key in a collection of arrays or objects.
$users = collect([
['name' => 'Alice', 'age' => 28],
['name' => 'Bob', 'age' => 34],
]);
$names = $users->pluck('name');
// ['Alice', 'Bob']
groupBy() - Grouping Data
The groupBy() method allows you to group collection items based on a given key or callback function.
$users = collect([
['name' => 'Alice', 'group' => 'A'],
['name' => 'Bob', 'group' => 'B'],
['name' => 'Charlie', 'group' => 'A']
]);
$groups = $users->groupBy('group');
// Group A: Alice, Charlie
// Group B: Bob
chunk() - Splitting the Collection into Smaller Pieces
The chunk() method breaks the collection into multiple smaller collections of a given size.
$collection = collect([1, 2, 3, 4, 5, 6, 7, 8]);
$chunks = $collection->chunk(3);
// [[1, 2, 3], [4, 5, 6], [7, 8]]
each() - Iterating Over the Collection
The each() method allows you to loop through each item in the collection and perform an action on it.
collect([1, 2, 3])->each(fn($num) => print($num));
// 1 2 3
contains() - Checking if a value exists
The contains() method checks if a given item is present in the collection.
$exists = collect([1, 2, 3])->contains(2);
pipe() - Passing the collection to a function
The pipe() method allows you to pass the entire collection into a function and return the result.
$result = collect([1, 2, 3])->pipe(function ($collection) {
return $collection->sum();
});
// 6
has() - Checking if a key exists
The has() method determines if a given key exists in the collection.
$collection = collect(['name' => 'Alice', 'age' => 28]);
$exists = $collection->has('age');
// true
dot() - Converting a Multi-Dimensional Array to Dot Notation
The dot() method transforms nested arrays into a flat array using dot notation.
$collection = collect(['user' => ['name' => 'Alice', 'email' => 'alice@example.com']]);
$dot = $collection->dot();
// ['user.name' => 'Alice', 'user.email' => 'alice@example.com']
isEmpty() - Checking if the collection is empty
The isEmpty() method returns true if the collection has no items.
$empty = collect([])->isEmpty();
// true
Conclusion
Laravel Collections make array manipulation way more intuitive and expressive. If you want to write cleaner and more elegant code, mastering them is a must!
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