Try Rector Online | Rector - Automated Way to Instantly Upgrade and Refactor any PHP code

Run Rector on your code to see what it can do for you:

 <?php
 
 final class DemoFile
 {
-	private Bar $foo;
-	
-	public function __construct(?Bar $foo = null) {
-		$this->foo = $foo ?? new Bar();
-	}
+	public function __construct(private readonly ?Bar $foo = new Bar())
+    {
+    }
     
     public function work(): string
     {

PHP snippet to change

<?php

final class DemoFile
{
	private Bar $foo;
	
	public function __construct(?Bar $foo = null) {
		$this->foo = $foo ?? new Bar();
	}
    
    public function work(): string
    {
        return $this->foo::class;
    }
}

class Bar {}

(new DemoFile(null))->work();

Applied Rules:

NewInInitializerRector
ReadOnlyPropertyRector

Not a change you expect?

Create an issue on GitHub

Config rector.php

<?php

use Rector\Config\RectorConfig;
use Rector\ValueObject\PhpVersion;

return RectorConfig::configure()
    ->withPhpSets(php81: true);

Rector version: 036cfd - released at 2026-02-24 16:36