You can delete / Destroy session using the PHP function unset()

Example

<?php
session_start();
if(isset($_SESSION[‘phpcodez_views’]))
unset($_SESSION[‘phpcodez_views’]);
?>

Also its possible to completely delete the data using the function session_destroy ()

Example
<?php
session_destroy();
?>

Before using a session variable ,we must check if that variable exists in $_SESSION array and that can be done using the function .

Example

<?php
session_start();
if(isset($_SESSION[‘phpcodez_views’]))
$_SESSION[‘phpcodez_views’] = $_SESSION[‘phpcodez_views’]+ 1;
else
$_SESSION[‘phpcodez_views’] = 1;
?>

When you want to store information in a session use $_SESSION – this is where you store and retrive session data .

Example

<?php
session_start();
$_SESSION[‘phpcodez_views’] = 1; // store data
echo $_SESSION[‘phpcodez_views’]; //retrieve data
?>

Before you begin storing information in PHP session , you must start the session and it must be mentioned at the very beggining of your code .

<?php session_start(); // start PHP session! ?>

Session variables are used to store values that are required across multiple web pages .

A website can not remember anything about the users those who have already visited the site since the HTTP request does not have state . But at time , it is necessary to remember some details(eg should understand if a user is logged in or not ) . In such case we can use session that enable the website to store the information for later use .