What is the usage of PHP sessions?

Session in PHP is a mechanism for passing and storing data between different pages. Session data is stored on the server, not on the user’s computer. Here is the basic usage of PHP sessions:

1. Initiate session: Before using a session, it must be initiated. Session can be initiated using the session_start() function, which should be called at the top of all PHP code and before any output.
2. Setting session variables: You can use the $_SESSION superglobal variable to set and access session data. For example, you can store a value in a session variable like $_SESSION[‘username’] = ‘John’;.
3. Accessing session variables: You can retrieve session data using the $_SESSION superglobal variable. For example, you can access the value stored in the session variable by using $_SESSION[‘username’].
4. End session: You can use the session_destroy() function to end the session and clear all session variables. This will invalidate the user’s current session.
5. By default, sessions end when a user closes their browser, but you can change this behavior by setting a session timeout. You can use the session_set_cookie_params() function to set the expiration time for the session.
6. Safety: When using sessions, it is important to consider security issues. Make sure to properly encrypt or handle sensitive data, such as passwords, before storing them.

Sessions can be used to store a user’s login status, shopping cart contents, user preferences, and other information across different pages. It provides a convenient way to track user sessions on the server side.