What's new in PHP 8.1

Non-final internal method return types are now declared.


<?php
class MyDateTime extends DateTime
{
    public function modify(string $modifier) { return false; }
}

To support PHP 7.4 through PHP 8.1:


&lt;?php
class MyDateTime extends DateTime
{
    /**
     * @return DateTime|false
     */
    *#[ReturnTypeWillChange]*
    public function modify(string $modifier) { return false; }
}