Creation of Dynamic Property is Deprecated

Why This Happens

Starting in PHP 8.2, creating properties that are not declared in the class definition triggers a deprecation notice. This will become an error in PHP 9.0. Dynamic properties were a source of subtle bugs because typos in property names would silently create new properties instead of failing.

The Problem

class User {
    public string $name;
}
$user = new User();
$user->name = 'Alice';
$user->fullName = 'Alice Smith'; // Dynamic property deprecated

The Fix

class User {
    public string $name;
    public string $fullName;
}
$user = new User();
$user->name = 'Alice';
$user->fullName = 'Alice Smith';

Step-by-Step Fix

1. 1

   Find the dynamic property

   Check the warning to see which property is being dynamically created and on which class.

2. 2

   Declare the property

   Add a typed property declaration to the class for the property that was being set dynamically.

3. 3

   Use AllowDynamicProperties if needed

   If the class intentionally uses dynamic properties, add the #[AllowDynamicProperties] attribute. But prefer declaring properties explicitly.