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sandip
answered Feb 28 '23 00:00
In PHP, a session is a way to store information about a user across multiple requests . Sessions allow you to store user-specific data on the server and associate it with a unique session ID that is sent to the user's browser as a cookie or through a URL parameter . The user's browser then sends the session ID back to the server with each subsequent request, allowing the server to retrieve the session data and continue where it left off.
Here's a brief overview of how PHP sessions work:
1. Session data is stored on the server in a temporary file or in a database. When a user visits a page for the first time, PHP creates a new session for that user and generates a unique session ID.
2. The session ID is sent to the user's browser as a cookie or through a URL parameter. The session ID is typically stored in a cookie, which is sent to the server with each subsequent request.
3. When the user makes a subsequent request, PHP reads the session ID from the cookie or URL parameter and retrieves the corresponding session data from the server.
4. The session data can be read and modified by PHP scripts as needed. For example, you might store user information like their name, email address, and preferences in the session data.
When the user logs out or their session expires, the session data is deleted from the server.
Here's an example of how to use PHP sessions to store user data:
// Start a new session
session_start();
// Set a session variable
$_SESSION['username'] = 'johndoe';
// Retrieve a session variable
$username = $_SESSION['username'];
// Destroy the session
session_destroy();
In this example, we start a new session using session_start(). We then set a session variable called username to the value 'johndoe'. We retrieve the value of the username variable using $_SESSION['username']. Finally, we destroy the session using session_destroy().
it is required to add session_start() function at every start of the php page where you want to use session.