oliverdavies.uk/source/_daily_emails/2023-04-16.md

---
title: >
    Refactoring with readonly classes in PHP 8.2
pubDate: 2023-04-16
permalink: >-
    archive/2023/04/16/refactoring-with-readonly-classes-in-php-8-2
tags:
    - php
---

Marian Kostadinov ([stochnagara on Twitter](https://twitter.com/stochnagara)) replied to Friday's email about DTOs and value objects to tell me about `readonly` classes, which can be done in PHP 8.2.

Looking at the previous class:

```php
class AccountDetails {

  public function __construct(
    public readonly string $accountNumber,
    public readonly string $sortCode,
  ) {}
  
}
```

Instead of setting each property as `readonly`, the whole class can instead be marked as `readonly`:

```php
readonly class AccountDetails {

  public function __construct(
    public string $accountNumber,
    public string $sortCode,
  ) {}
  
}
```

Thanks for the suggestion, Marian!