php - Codeigniter add new item to current session userdata array -

so have array:

$data = array(   'item_1' => $this->input->post('item_1'),   'item_2' => $this->input->post('item_2'),   'item_3' => $this->input->post('item_3') );  $this->session->set_userdata( 'items', $data ); 

and want add new item array, updated array of userdata this:

$data = array(       'item_1' => $this->input->post('item_1'),       'item_2' => $this->input->post('item_2'),       'item_3' => $this->input->post('item_3'),       'item_4' => $this->input->post('item_4') );  $this->session->set_userdata( 'items', $data ); 

how that, thank you

follow these steps add data current session:

$data            = $this->session->userdata('items'); $data['item_4']  = $this->input->post('item_4'); $this->session->set_userdata('items', $data); 

here, first take out current session items in array, add item array, can array_push() prefer above. now, set session updated data.