PHP Sessions

What are PHP Sessions?

PHP sessions are a way to store information across different pages of a website. Unlike cookies, session data is stored on the server, which provides more security. Sessions are useful for maintaining user-specific data such as login information, shopping cart contents, and other personalized data.

Starting a PHP Session

Once session_start() is called, PHP will either resume an existing session or start a new one. Each session is identified by a unique session ID, which is usually stored in a cookie on the user's computer.

Storing and Accessing Session Data

For example, to store a user's favorite color:

To retrieve the session data elsewhere in your application:

Regenerating Session IDs

To enhance security, it's a good practice to regenerate the session ID periodically using session_regenerate_id(). This function changes the session ID while keeping the session data, which helps prevent session fixation attacks.

Destroying a Session

When a session is no longer needed, it can be destroyed using session_destroy(). This function deletes all data associated with the session. It is a good practice to also unset the session variables and delete the session cookie.