Cannot indirectly modify readonly property %s::$%s

Description

A readonly property cannot be changed after it was set. This includes trying to reach the property via a reference.

Example

<?php

class X {
    readonly public string $property;

    public function __construct() {
        $this->property = 'A';
    }
}

$object = new X;
$variable =& $object->property;

?>

Literal Examples

• Cannot indirectly modify readonly property X::$property

Solutions

• Do not create a reference to a readonly property.