Parameter $%s of %s hook %s::$%s must not have a default value¶

Description¶

The parameter of a set property hook cannot declare a default value. The hook is always invoked with the value being assigned to the property, so a default value would never actually be used, and PHP rejects it as meaningless.

Example¶

<?php

class X
{
    public string $property {
        set(string $value = 'default') {
            $this->property = $value;
        }
    }
}

?>

Literal Examples¶

Parameter $value of set hook X::$property must not have a default value

Solutions¶

Remove the default value from the hook’s parameter.
If a fallback value is needed, assign a default to the property itself, or handle it inside the hook’s body.

Changed Behavior¶

This error may appear following an evolution in behavior, in previous versions. See ` <https://php-changed-behaviors.readthedocs.io/en/latest/behavior/.html>`_.