Codeigniter session will not unset

Question

im working on a community, and i want to user to log off but it dosent unset the userdata :S, do you know why?

this is my controller function

function logOff() {

        //$this->session->flashdata('reports', 'Du er logget af');

        //redirect('frontpage', 'refresh');
        $this->session->unset_userdata($sessionData);


    }

Answer 1

You can destroy an entire session by calling the following:

$this->session->sess_destroy();

Answer 2

You need to specify what elements you want to unset individually rather than a variable or object as per your code:

$this->session->unset_userdata($sessionData);

Instead use to remove the login information so you still preserve a basket or whatever else you have stored:

$this->session->unset_userdata('userid');

Or destroy the whole session:

$this->session->sess_destroy();  //as per Yorick's answer