Why session variables are being used.Explain?
Session variables are used to store user information that can be used across multiple pages of a website . When a user interacts with a website, the web server does not know who the user is or what the user is doing because HTTP is a stateless protocol . Session variables solve this problem by storing user information on the server and associating it with a unique session ID that is sent to the user’s browser as a cookie .
Session variables are set using the $_SESSION superglobal variable in PHP . The session_start() function must be called at the beginning of each page that uses session variables to start or resume a session . Once a session has been started, session variables can be set, retrieved, and modified using the $_SESSION superglobal variable .By default, session variables last until the user closes their browser.
Session variables are commonly used to store user-specific information such as login credentials, shopping cart contents, and user preferences . They can also be used to prevent unauthorized access to certain pages or features of a website by checking whether a user is logged in or has the necessary permissions.
Here’s an example of how session variables can be used in PHP:
<?php
// Start the session
session_start();
// Set session variables
$_SESSION["username"] = "Vishal";
$_SESSION["favcolor"] = "black";
echo "Session variables are set.";
?>
In this example, we start a new PHP session using session_start(). We then set two session variables using the $_SESSION superglobal variable: $_SESSION[“username”] and $_SESSION[“favcolor”]. These variables can now be accessed from any page that uses the same session ID.
Here’s an example of how to retrieve session variable values:
<?php
// Start the session
session_start();
// Retrieve session variables
echo "Username is " . $_SESSION["username"] . ".<br>";
echo "Favorite color is " . $_SESSION["favcolor"] . ".";
?>
In this example, we retrieve the values of $_SESSION[“username”] and $_SESSION[“favcolor”] using the $_SESSION superglobal variable.
