Codeigniter：Session_id为空

Question

I have a probleme in PHP Codeigniter, I'm trying to get the sessions Id, but it returns an empty string,

this is my code (ControllerTest.php):

class ControllerTest extends CI_Controller
{   
    public function test(){
        echo "session: ".$this->session->userdata('session_id');
    }
}

And in autoload.php i have this :

$autoload['libraries'] = array('database', 'session');

and in the output, i only get this : session:

EDIT :

And when I print the session print_r($this->session->userdata); i get this:

Array ( [__ci_last_regenerate] => 1441821744 )

And if i try ro access the ip_address like this :

$this->session->userdata('ip_address');

It also returns an empty string

Answer 1

1. Try this

   $session_id = $this->session->userdata('session_id');

2. Try this,

   $this->session->all_userdata();

And returns an associative array like the following:

Array
(
    [session_id] => 4a5a5dca22728fb0a84364eeb405b601
    [ip_address] => 127.0.0.1
    [user_agent] => Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_7;
    [last_activity] => 1303142623
)