How to store data in a PHP Session?

In PHP, sessions provide a way to persist data across multiple page requests for a single user. Storing data in a session allows developers to maintain user-specific information such as login status, user preferences, shopping cart items, etc.

Syntax:

// Start or resume a session
session_start();

// Store data in the session
$_SESSION['key'] = $value;

Important:

• Before storing or accessing session data, it’s essential to start or resume the session using session_start().
• Data is stored in the $_SESSION superglobal array, using associative keys to identify the stored values.
• Session data persists until the session is explicitly destroyed or expires due to inactivity.

$_SESSION	Cookies
Stores data on the server side	Stores data on the client side
Persists until the session ends	Can have an expiration date
Suitable for sensitive data	Limited in size and can be manipulated by the client

Usage

• Use sessions to store user authentication information such as user ID, username, or login status to maintain user sessions across multiple pages.

Example: Upon successful login, store the user ID in the session to authenticate subsequent page requests.

• Utilize sessions to store shopping cart items, quantities, and prices to maintain the state of the user’s shopping cart across page requests.

Example: Store the selected items and quantities in the session as the user adds products to the cart, allowing seamless navigation between different pages while preserving the shopping cart contents.