Laravel Collections – What are they? How to use them?

9 Min | April 24, 2024

Laravel Collections provides a powerful way to work with data arrays in your Laravel applications. Collections are a type of fluent, array-like data structure that extends the native PHP array to provide a variety of helpful methods for working with data sets.

At their core, Laravel collections are simply arrays with additional helper methods. Many collection methods allow you to chain further methods, allowing for more expressive code compared to simple PHP arrays. Some standard collection methods include mapping, filtering, sorting, reducing, etc. Collections make it simpler to iterate, manipulate, and extract data from arrays.

Collections are significant in Laravel because many Laravel features return Collections instead of plain arrays. For example, retrieving data from your database using Eloquent will return the results as a Collection object. This allows you to chain query builder and collection methods expressively. Collections power many of Laravel’s best features.

Some key advantages of using Collections in Laravel include:

  • More concise, expressive code for manipulating data sets
  • Helper methods like sort, filter, map, and reduce to transform arrays
  • Easy chaining of additional methods
  • Works well with Eloquent results and relationships
  • Consistent APIs for working with data
  • Active community support and momentum

Laravel Collections makes a developer’s life easier by providing a straightforward, unified API for working with data arrays more expressively. Collections combined with Eloquent integrations make Laravel a very productive framework for building web applications. So, let’s dive into it.

Getting Started with Laravel Collections

No additional installation is needed to use Laravel Collections as they are included out of the box with the Laravel framework. If you have Laravel installed, you can access Collections and the available methods.

The simplest way to create a collection is to wrap an array with the collect() helper method:

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

You can also create an empty collection to which you can later add items:

$collection = collect();

$collection->add(1);

$collection->add([2, 3]);

The collection methods allow you to easily manipulate data sets and transform arrays more simply than manual iterations and loops.

Understanding the Anatomy of Laravel Collections

Core Concepts

Iterable Interface

Laravel collections implement PHP’s Iterable interface, allowing them to be looped over using foreach loops:

foreach($collection as $item) {

//

}

Lazy Collections

Laravel collections are considered “lazy collections.” This means the transformation methods like map, filter, and others will be executed/evaluated once iteration occurs. This allows for chaining several methods together without any performance penalty.

Transformation Methods

Map

The map method iterates over the collection and passes each value to the given callback, replacing each value with the returned result from the callback:

$mapped = $collection->map([

return $item * 2;

]);

Filter

The filter method filters the collection by passing each value to the callback and keeping only values where the callback returns true:

$filtered = $collection->filter(function ($item) {

return $item > 2;

});

Each

Each method iterates over the collection and passes each item to a callback:

$collection->each(function ($item) {

//

});

Reduction Methods

Reduce

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

$total = $collection->reduce(function ($carry, $item) {

return $carry + $item;

});

Sum

The sum method returns the sum of all items in the collection:

$sum = $collection->sum();

Avg

The average method returns the average value of all items in the collection:

$avg = $collection->avg();

Advanced Usage of Laravel Collections

Chaining Methods

One of the most powerful parts of Laravel collections is the ability to chain multiple methods together to form method “pipelines”:

$collection = collect([1, 2, 3, 4]);

$filtered = $collection->filter(function ($item) {

return $item > 2;

})->map(function ($item) {

return $item * 2;

});

The code reads clearly while applying multiple transformations to the collection.

Custom Collections

You can even subclass IlluminateSupportCollection to make custom collection types:

class MyCollection extends IlluminateSupportCollection {}

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

You can add your methods available on all instances of your custom collection.

Collection Macros

Macros allow you to define custom methods that will be available on all collections globally:

Collection::macro('multiply', function () {

return $this->map(function ($item) {

return $item * 2;

});

});

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

$ multiplied = $collection->multiply();

Now, your custom macro is usable on all collections.

Practical Examples and Use Cases

Working with Eloquent Models

Laravel collections integrate nicely with Eloquent models. For example, you can filter and manipulate a model’s relations easily:

$user->products()->filter(function ($product) {

return $product->price > 100;

})->each(function ($product) {

//

});

Manipulating Array Data

Collections make working with API response data easier:

$response = Http::get('/data');

$parsed = collect($response->json())->map(function ($item) {

return formatItem($item);

})

Streamlining Data Processing

You can leverage collections to preprocess data before displaying it:

$reportData = getData();

$processed = collect($reportData)->filter()->sort()->take(100)->map()->toArray();

return view(‘reports’, [‘data’ => $processed]);

This allows cleaner controller logic and less processing code.

Some other examples include aggregating totals, statistics, manipulating multidimensional arrays, and more. The methods available in collections cover many common data manipulation cases.

Overall, collections help streamline workflows for preparing, processing, and displaying data in a web application powered by Laravel. They form a crucial component allowing Laravel to create expressive, readable code.

Optimizing Performance with Laravel Collections

Lazy Evaluation

As mentioned earlier, Laravel collections delay executing most operations until iteration occurs. This means you can chain together many methods without any immediate performance penalty:

$collection = Collection::make(HugeDataSet());

$filtered = $collection->filter()->map()->sort()->take(100);

// No actual work done yet

The processing is optimized only to run what is required.

Minimizing Memory Footprint

Collections allow handling large datasets without loading everything into memory using lazy evaluation:

$collection = collect($megaDataSet);

// Only ten models loaded at a time

$collection->take(10)->each(function ($item) {

// Process in batches of 10 models

});

Best Practices

Some tips for optimal collection performance:

  • Use lazy evaluation to avoid premature optimization
  • Test bottlenecks before optimizing
  • Filter early when needed to minimize the dataset
  • Map over direct property access when possible
  • Measure the impact of custom macros or class extensions

The deferred execution model means you can write expressive code using collections and only optimize where truly necessary.

Integration with Other Laravel Components

Collections and Blade Templates

It’s easy to iterate over collections in Blade using foreach:

@foreach($collection as $item)

<!– Display item –>

@endforeach

You can also pass collections directly to Blade views from route controllers.

Collections and API Responses

The response helpers integrate nicely with collections for API responses:

return response()->json(

Collection::make($data)

->map->transform()

->filter()

);

This approach looks clean and uses collection methods for preparing API response payloads.

Collections and Eloquent Relationships

As mentioned already, Eloquent uses collections for relationships:

$user->products()->filter->active()->get();

Before loading the final results, you can filter and process relationship data with collection methods.

Collections integrate seamlessly across core Laravel components like views, responses, and Eloquent models. They power many areas of the framework’s functionality behind the scenes.

Conclusion

Laravel collections provide a robust way of interacting with array data powered by an expressive, fluent interface. Under the hood, collections utilize deferred execution and the concept of transformation pipelines to enable chaining multiple methods together without incurring immediate performance penalties.

This lazy evaluation allows you to write code that reads clearly while only running operations as needed. Data manipulation methods like map, filter, and reduce commonly cover most use cases when working with arrays in Laravel.

And because collections integrate seamlessly with core components like Blade templates, Eloquent models, and API response helpers, they form a natural part of developing web applications with Laravel. For example, collection methods combine effortlessly with querying data from databases through Eloquent relationships.

Furthermore, collections handle large datasets well thanks to optimized memory usage strategies like processing items in batch via cursors. There are also plenty of learning resources between the official Laravel documentation and the wealth of community knowledge in tutorials and advanced articles.

In summary, Laravel collections are a syntactically beautiful and practical way to interact with arrays and iterable data. They make a developer’s life easier by providing powerful helpers for mundane tasks while integrating seamlessly across the Laravel ecosystem. Collections unlock a more productive, enjoyable developer experience.

Some suggestions for further improving your collection skills include reading in-depth documentation, watching video tutorials, exploring advanced community posts, practicing on your projects, reviewing third-party packages, and diving into the source code.

Our blog post on learning Laravel also covers various ways to master Laravel overall. With continued practice, collections can take your Laravel capabilities to all new levels. Let me know if you have any other collection-related questions!

Frequently Asked Questions

What are some real-world use cases for Laravel collections?

Laravel collections shine when you need to filter, transform, or extract data from Eloquent results, APIs, CSV imports, and other data sources. They simplify workflows like aggregating statistics, sorting data for display, paginating results, and preprocessing API responses.

When should I use a collection over a traditional array?

Use collections when manipulating, iterating, or working with array data. The helpful methods make actions like filtering, mapping, and reducing more expressive. Collections also integrate nicely across the Laravel ecosystem.

How can collections help me work with large data sets efficiently?

Collections allow you to process extensive data in chunks using lazy evaluation without loading the entire dataset into memory. Methods like chunk and cursor let you define how many records to work with simultaneously.

What are some key things to know about performance with collections?

Leverage lazy evaluation to avoid premature optimization. Filter data early when possible to minimize what you process. Test actual bottlenecks before trying to optimize. Understand which operations are executed immediately vs deferred.

Where can I find more examples of advanced usage of collections?

The Laravel documentation has additional collection examples. Also, check out blog posts on Medium and DevDojo or video tutorials on Laracasts. The Laravel News newsletter features regular community articles on collections.

How can I extend collections with custom functionality?

You can define custom collection macros to add reusable methods or even create custom collection subclasses by extending IlluminateSupportCollection.

The Author

Anmol is a dedicated technical content writer known for her practical approach. She believes in experiencing processes firsthand before translating them into insightful content. Additionally, she is good at WordPress development and skills of digital forensics and cybersecurity. Beyond her professional endeavors, she enjoys playing sports games, particularly table tennis and badminton, valuing the balance between mental and physical agility.

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