What are the limitations of setting cookies across multiple domains in PHP?

Setting cookies across multiple domains in PHP is limited due to the SameSite attribute restrictions, which prevent cookies from being shared across different domains for security reasons. To work around this limitation, you can set the domain parameter of the setcookie function to a common root domain that all the domains share. This allows the cookies to be accessible across all the specified domains.

$cookieName = 'example_cookie';
$cookieValue = 'example_value';
$cookieDomain = '.example.com';

setcookie($cookieName, $cookieValue, time() + 3600, '/', $cookieDomain);