Default values | laravel-data | Spatie

 SPATIE

  Laravel Data
===============

spatie.be/open-source

  [Docs](https://spatie.be/docs)  [Laravel-data](https://spatie.be/docs/laravel-data/v4)  As-a-data-transfer-object  Default values

 Version   v4   v3   v2   v1

 Other versions for crawler [v4](https://spatie.be/docs/laravel-data/v4) [v3](https://spatie.be/docs/laravel-data/v3) [v2](https://spatie.be/docs/laravel-data/v2) [v1](https://spatie.be/docs/laravel-data/v1)

- [ Introduction ](https://spatie.be/docs/laravel-data/v4/introduction)
- [ Support us ](https://spatie.be/docs/laravel-data/v4/support-us)
- [ Requirements ](https://spatie.be/docs/laravel-data/v4/requirements)
- [ Installation & setup ](https://spatie.be/docs/laravel-data/v4/installation-setup)
- [ Third party packages ](https://spatie.be/docs/laravel-data/v4/third-party-packages)
- [ Questions and issues ](https://spatie.be/docs/laravel-data/v4/questions-issues)
- [ Changelog ](https://spatie.be/docs/laravel-data/v4/changelog)
- [ About us ](https://spatie.be/docs/laravel-data/v4/about-us)

Getting started
---------------

- [ Quickstart ](https://spatie.be/docs/laravel-data/v4/getting-started/quickstart)

As a DTO
--------

- [ Creating a data object ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/creating-a-data-object)
- [ Nesting ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/nesting)
- [ Collections ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/collections)
- [ Abstract Data ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/abstract-data)
- [ Casts ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/casts)
- [ Optional properties ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/optional-properties)
- [ Mapping property names ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/mapping-property-names)
- [ Default values ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/defaults)
- [ Computed values ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/computed)
- [ From a request ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/request-to-data-object)
- [ From a model ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/model-to-data-object)
- [ Injecting property values ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/injecting-property-values)
- [ Factories ](https://spatie.be/docs/laravel-data/v4/as-a-data-transfer-object/factories)

Validation
----------

- [ Introduction ](https://spatie.be/docs/laravel-data/v4/validation/introduction)
- [ Auto rule inferring ](https://spatie.be/docs/laravel-data/v4/validation/auto-rule-inferring)
- [ Using validation attributes ](https://spatie.be/docs/laravel-data/v4/validation/using-validation-attributes)
- [ Manual rules ](https://spatie.be/docs/laravel-data/v4/validation/manual-rules)
- [ Working with the validator ](https://spatie.be/docs/laravel-data/v4/validation/working-with-the-validator)
- [ Nesting Data ](https://spatie.be/docs/laravel-data/v4/validation/nesting-data)
- [ Skipping validation ](https://spatie.be/docs/laravel-data/v4/validation/skipping-validation)

As a resource
-------------

- [ From data to array ](https://spatie.be/docs/laravel-data/v4/as-a-resource/from-data-to-array)
- [ From data to resource ](https://spatie.be/docs/laravel-data/v4/as-a-resource/from-data-to-resource)
- [ Mapping property names ](https://spatie.be/docs/laravel-data/v4/as-a-resource/mapping-property-names)
- [ Appending properties ](https://spatie.be/docs/laravel-data/v4/as-a-resource/appending-properties)
- [ Wrapping ](https://spatie.be/docs/laravel-data/v4/as-a-resource/wrapping)
- [ Including and excluding properties ](https://spatie.be/docs/laravel-data/v4/as-a-resource/lazy-properties)
- [ Transforming data ](https://spatie.be/docs/laravel-data/v4/as-a-resource/transformers)

Advanced usage
--------------

- [ Eloquent casting ](https://spatie.be/docs/laravel-data/v4/advanced-usage/eloquent-casting)
- [ Transforming to TypeScript ](https://spatie.be/docs/laravel-data/v4/advanced-usage/typescript)
- [ Working with dates ](https://spatie.be/docs/laravel-data/v4/advanced-usage/working-with-dates)
- [ Normalizers ](https://spatie.be/docs/laravel-data/v4/advanced-usage/normalizers)
- [ Pipeline ](https://spatie.be/docs/laravel-data/v4/advanced-usage/pipeline)
- [ Creating a cast ](https://spatie.be/docs/laravel-data/v4/advanced-usage/creating-a-cast)
- [ Creating a transformer ](https://spatie.be/docs/laravel-data/v4/advanced-usage/creating-a-transformer)
- [ Creating a rule inferrer ](https://spatie.be/docs/laravel-data/v4/advanced-usage/creating-a-rule-inferrer)
- [ Use with Inertia ](https://spatie.be/docs/laravel-data/v4/advanced-usage/use-with-inertia)
- [ Use with Livewire ](https://spatie.be/docs/laravel-data/v4/advanced-usage/use-with-livewire)
- [ Internal structures ](https://spatie.be/docs/laravel-data/v4/advanced-usage/internal-structures)
- [ Mapping rules ](https://spatie.be/docs/laravel-data/v4/advanced-usage/mapping-rules)
- [ Validation attributes ](https://spatie.be/docs/laravel-data/v4/advanced-usage/validation-attributes)
- [ Get data from a class quickly ](https://spatie.be/docs/laravel-data/v4/advanced-usage/get-data-from-a-class-quickly)
- [ Performance ](https://spatie.be/docs/laravel-data/v4/advanced-usage/performance)
- [ Commands ](https://spatie.be/docs/laravel-data/v4/advanced-usage/commands)
- [ Traits and interfaces ](https://spatie.be/docs/laravel-data/v4/advanced-usage/traits-and-interfaces)
- [ In Packages ](https://spatie.be/docs/laravel-data/v4/advanced-usage/in-packages)
- [ Available property mappers ](https://spatie.be/docs/laravel-data/v4/advanced-usage/available-property-mappers)

 Default values
==============

There are a few ways to define default values for a data object. Since a data object is just a regular PHP class, you can use the constructor to set default values:

```
class SongData extends Data
{
    public function __construct(
        public string $title = 'Never Gonna Give You Up',
        public string $artist = 'Rick Astley',
    ) {
    }
}
```

This works for simple types like strings, integers, floats, booleans, enums and arrays. But what if you want to set a default value for a more complex type like a `CarbonImmutable` object? You can use the constructor to do this:

```
class SongData extends Data
{
    #[Date]
    public CarbonImmutable|Optional $date;

    public function __construct(
        public string $title = 'Never Gonna Give You Up',
        public string $artist = 'Rick Astley',
    ) {
        $this->date = CarbonImmutable::create(1987, 7, 27);
    }
}
```

You can now do the following:

```
SongData::from();
SongData::from(['title' => 'Giving Up On Love', 'date' => CarbonImmutable::create(1988, 4, 15)]);
```

Even validation will work:

```
SongData::validateAndCreate();
SongData::validateAndCreate(['title' => 'Giving Up On Love', 'date' => CarbonImmutable::create(1988, 4, 15)]);
```

There are a few conditions for this approach:

- You must always use a sole property, a property within the constructor definition won't work
- The optional type is technically not required, but it's a good idea to use it otherwise the validation won't work
- Validation won't be performed on the default value, so make sure it is valid