How to separate index.php content for registered users and guests in WordPress?

Question

PHP

Actually, there is a WordPress site and a rewritten authorization form, which is called through <?php wp_login_form( $args ); ?>
Next, after authorization on the site, the form remains active and does not disappear (you can log in again), you need to somehow force the content on the site to change, for example, change links in navigation, such as adding an exit button, personal account or viewing messages. And of course, remove the re-authorization
So, how to distinguish the content of registered users and guests in index.php?
What functions or scripts do all this?

Answer 1

https://developer.wordpress.org/reference/function...