How to print data like username after login[php- codeigniter]

Question

I try to print user id and it works but when I try to print username i try different methods from net but nothing works for me. can someone help me to print username :D

looks like this: what it shows

View:

<h1>Hi <?php echo $_SESSION['user_id'];?></h1>
    <h1>Hi <?php echo $_SESSION['username'];?></h1>

Controller:

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Login extends CI_Controller {

    public function index()
    {
        if (isset($_SESSION['user_id'])){
            redirect("admin/dashboard");
        }
        $data=[];
        if (isset($_SESSION['error'])){
            $data['error']=$_SESSION['error'];
        }else{
            $data['error']="NO_ERROR";
        }
        $this->load->view('adminpanel/loginview',$data);
    }
    function login_post(){
        print_r($_POST);
        if (isset($_POST)){
            $email=$_POST['email'];
            $password=$_POST['password'];

            $query = $this->db->query("SELECT * FROM `backenduser` WHERE `username`='$email' AND `password`='$password'");

            if ($query->num_rows()){
                $result= $query->result_array();
                //echo"<pre>";
                //print_r($result);
                **$this->session->set_userdata('user_id',$result[0]['uid']);
                $_SESSION['username']=$result->username;**
                redirect('admin/dashboard');
            }else{
                $this->session->set_flashdata('error','Invalid Credentials');
                redirect('admin/login');
            }
        }else{
            die("invalid input!");
        }
    }
}

Answer 1

Assumption:- you are getting user data in $result variable as same as you get id

function login_post(){
print_r($_POST);
if (isset($_POST)){
    $email=$_POST['email'];
    $password=$_POST['password'];

    $query = $this->db->query("SELECT * FROM `backenduser` WHERE `username`='$email' AND `password`='$password'");

    if ($query->num_rows()){
        $result= $query->result_array();
        //echo"<pre>";
        //print_r($result);
    

        $session_data = array(
                'user_id' => $result[0]['uid'],
                'username' => $result[0]['username'],
             
            );
            $this->session->set_userdata($session_data);

        redirect('admin/dashboard');
    }else{
        $this->session->set_flashdata('error','Invalid Credentials');
        redirect('admin/login');
    }
}else{
    die("invalid input!");
}