The session class in CodeIgniter allows the user to maintain a user’s “state” and track their activity while browsing the website. The session can be initialized using the library and auto-loaded in the environment using the following command.
$this->load->library('session');
Set the session variable: Session indexes can be assigned using key-value pairs. A particular key can be assigned to a value using the assignment operator. The value may be a string, key, or even an array.
Syntax:
$_SESSION['key'] = value;
Example 1:
PHP
<?PHP // Starting a new session session_start(); $_SESSION['id'] = 9 ; // Check if the session name exists if( isset($_SESSION['id']) ) { echo 'Session id is '.$_SESSION['id'].'<br>'; } else { echo 'Set the session id first '.'<br>'; } echo'<br>'; // Modifying the value of session $_SESSION['id'] = -8 ; echo 'New session id is '.$_SESSION['id'].'<br>'; ?> |
Output:
Session id is 9 New session id is -8
The session value can also be assigned using the set_userdata() method in CodeIgniter. This method takes a key as the first argument and the. next is the value to be assigned.
Syntax:
set_userdata ('key' , value)
Multiple key-value pairs can also be added at the session index in CodeIgniter, indicated by the following code snippet.
Example 2:
PHP
<?php // Setting multiple key values $sess_arr = array('id'=>5, 'name' => 'yash'); // Setting index at logged_in $this->session->set_userdata('logged_in', $sess_arr); // Printing the contents at this index print_r($_SESSION['logged_in']); ?> |
Output:
Array ( [id] => 5 [name] => yash )
Unset the session variable: The session variable can be unset by assigning it to a NULL value. This destroys the value stored at this key value.
Syntax:
$_SESSION['ey'] = NULL
Example 3:
PHP
<?php // Starting a new session session_start(); // Setting multiple values $sess_arr = array('id'=>5, 'name' => 'yash'); $_SESSION['logged_in']= $sess_arr; echo ('Old session : '); print_r ($_SESSION['logged_in']); echo '</br>'; // Unsetting the value $_SESSION['logged_in']= NULL; echo ('New session? : '); print_r ($_SESSION['logged_in']); ?> |
Output:
Old session : Array ( [id] => 5 [name] => yash ) New session? :
