(PHP 8 >= 8.2.0)
This attribute is used to mark classes that allow dynamic properties.
Dynamic properties are deprecated as of PHP 8.2.0, thus using them without marking the class with this attribute will emit a deprecation notice.
<?php
class DefaultBehaviour { }
#[\AllowDynamicProperties]
class ClassAllowsDynamicProperties { }
$o1 = new DefaultBehaviour();
$o2 = new ClassAllowsDynamicProperties();
$o1->nonExistingProp = true;
$o2->nonExistingProp = true;
?>Output of the above example in PHP 8.2:
Deprecated: Creation of dynamic property DefaultBehaviour::$nonExistingProp is deprecated in file on line 10