How can you check if a PHP session exists?

Question

Just wondering how to check if a PHP session exists... My understanding is that no matter what, if I am using sessions, I have to start my files with session_start() to even acc

Answer 1

In PHP there is something called the session name. The name is co-related to the cookie that will be being set if the session was already started.

So you can check the $_COOKIE array if there is a session cookie available. Cookies are normally the preferred form to interchange the session id for the session name with the browser.

If a cookie already exists this means that a PHP session was started earlier. If not, then session_start() will create a new session id and session.

A second way to check for that is to check the outgoing headers if the cookie for the session is set there. It will be set if it's a new session. Or if the session id changed.