62 lines
1.4 KiB
Markdown
62 lines
1.4 KiB
Markdown
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---
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title: Using readonly in PHP
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date: 2025-02-13
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permalink: daily/2025/02/13/readonly
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tags:
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- software-development
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- php
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cta: ~
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snippet: |
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Did you know you can make classes and properties read-only since PHP 8.1?
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---
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Since PHP 8.1, properties on PHP classes have been able to be marked as `readonly`.
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Once they've been set, they can't be changed or overwritten.
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This is great for data transfer objects (DTOs) that you want to be immutable and know the values are the same as when they were set.
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Here's an example:
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```php
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class MyDto {
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public function __construct(
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public readonly string $name,
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public readonly int $age,
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) {
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}
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}
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```
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I don't need to make the properties private or protected and write getter methods for them.
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I can make them public, knowing the values can't be changed.
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## readonly classes
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Since PHP 8.2, the entire class can be `readonly`, making the code cleaner and easier to read.
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This class does the same as the previous example:
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```php
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readonly class MyDto {
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public function __construct(
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public string $name,
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public int $age,
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) {
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}
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}
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```
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## Here's the thing
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This is a great example of how the PHP language continues to evolve and improve, and it's been a great way to make it easier to keep my code clean and with fewer bugs.
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If you want a way to easily add `readonly` to properties or classes, [take a look at Rector][0] which can automate it for you.
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[0]: {{site.url}}/daily/2025/01/31/rector
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