在Codeigniter中将uri段变量从一个函数传递到另一个函数

Hi looking for some help. I recently started coding with Codeigniter.

I have 2 functions within the same controller. I need 'uri segment' from first function to second. Tried to google but no success.

Here is my controller:

public item_page() {
    $id = $this->uri->segment(3);
    $this->load->view('view');
}

public validation() {
    // Form Validation Goes Here
    if($this->form_validation->run() == FALSE) {
        $this->session->set_userdata('validation_errors', validation_errors());
        redirect('item-page/'.$id); // I need variable here
    } else {
    redirect('execute');
    }
}

you can some Attribute in your class(controller)

controller:

private $page_id;

public item_page() {
    $id = $this->uri->segment(3);
    $this->page_id=$id;
    $this->load->view('view');
}

public validation() {
    // Form Validation Goes Here
    if($this->form_validation->run() == FALSE) {
        $this->session->set_userdata('validation_errors', validation_errors());
        redirect('item-page/'.$this->page_id); // I need variable here
    } else {
    redirect('execute');
    }
}

////// Method 2:

public item_page() {
        $id = $this->uri->segment(3);
        $this -> session -> set_userdata('id', $id);
        $this->load->view('view');
    }

    public validation() {
        // Form Validation Goes Here
        if($this->form_validation->run() == FALSE) {
            $this->session->set_userdata('validation_errors', validation_errors());
            redirect('item-page/'.$this -> session -> userdata("id")); // I need variable here
        } else {
        redirect('execute');
        }
    }

hope this help.