PHP Starting & Storing a Session
Posted by tutor | Posted in PHP Tutorial | Posted on 15-12-2009-05-2008
0
Whenever a user logs in to a system some variables are set to identify this same user throughout his working duration and when the user logs out of the system the variables are reset. This duration from log=in to log-out is called a session and the variables used are session variables to identify a session.
Starting a PHP Session
Before storing the user information in a session, it should be first started. The code to start a session must be at the very beginning of your code, before any HTML or text is sent.
<html>
<body>
………….
</body>
</html>
The code above will register the user’s session with the server, allow you to start saving user information, and assign a UID for that user’s session.
Storing a Session Variable
When you want to store user data in a session use the built-in PHP associative array $_SESSION. This is where you both store and retrieve session data. In previous versions of PHP there were other ways to perform this store operation, but it has been updated and this is the correct way to do it.
session_start();
// store session data
$_SESSION['username']=”Tutor”;
?>
<html>
<body>
<?php
//retrieve session data
echo “Username=”. $_SESSION['username'];
?>
</body>
</html>
Username=Tutor
In the example below, we create a simple page-views counter. The isset() function checks if the “views” variable has already been set. If “views” has been set, we can increment our counter. If “views” doesn’t exist, we create a “views” variable, and set it to 1:
session_start();
if(isset($_SESSION['views']))
$_SESSION['views']=$_SESSION['views']+1;
else
$_SESSION['views']=1;
echo “Views=”. $_SESSION['views'];
?>
