Unsetting PHP Session

Unsetting php session you must read my previous article setting php session to get better understand it. Now in Setting php session we had set the username in set.php and in view we had store username into the session. Now we will create another file unset.php which you can say logout the user. Unset is keyword to remove the stored session variable.

Code for Unsetting php session

set.php (Screenshot1)

Set.php Screenshot1

<?php

session_start();



$_SESSION['username']='alex';

?>

View.php (Screenshot2)

Screenshot2

<?php

session_start();



if (isset($_SESSION['username'])) {

echo 'Welcome. '.$_SESSION['username']';



}else {

echo 'Please log in.';

}



?>

Unset.php (Screenshot3)

Screenshot3

<?php



session_start();



unset($_SESSION['username']);

?>

Output (Screenshot4 , Screenshot5 , Screenshot6):-

Screenshot4

Screenshot5

Screenshot6

Now As you can See in Screenshot4 , Screenshot5 We had unset the variables which is stored in session alex and in Screenshot 6 its again asking for please login now You. Try Your self by again setting php Session and Unsetting php Session. 

For Example If You will not rewrite session_start() in unset.php. It will not remove variable from the session and session will not be unset. 

Let See All output for all set.php , view.php and unset.php

Screenshot7

Opening set.php file for setting username as a session variable 

Screenshot8

$_SESSION['username']='alex'; is set to the session variable.

Screenshot9

viewing view.php

Screenshot10

Shows welcome Alex as we can see the Session variable called alex.

Screenshot11

Unset.php file opening

Screenshot12

Will unset the variable which had been set by set.php 

Screenshot13

Now You can see view.php is in condition of else because the session variable is unset by unset.php. 

Now What if i have more then one session to unset. If i want to unset all session that exit . For That you can try your self 

Code for unsetting php session

unset.php

<?php

session_start();

session_destroy();

?>

Output (Screenshot14 , Screenshot15 , Screenshot16 , Screenshot17)

Screenshot14

Screenshot15

Screenshot16

Screenshot17

Now this session_destroy will unset all session of the website. It will remove all variables of the session which are stored in session.

In Screenshot 17 you can see all session variable had been removed