How do I store multiple variables in a single session?

Question

This is what I have, what do I do? I want to store two variables in a single session, they are username and avatar.

if ($count == 1) 
{
$row = mysqli_fetch_array($result);
//while ($_SESSION['username'] = $row['username'])
$_SESSION['users'] = [''];
$_SESSION['users']['username'] = $row['username'];
$_SESSION['users']['avatar'] = $row['avatar'];

{
session_start();

Answer 1

Is there a reason you can't use:

$_SESSION['username'] = $row['username'];
$_SESSION['avatar'] = $row['avatar'];

Answer 2

First: Use session_start(); of the top of your code.

Second: What you mean with this row? "$_SESSION['users'] = [''];" If you want to initialize it you should use:

$_SESSION['users'] = array();

In short your code should like:

session_start();
.
.
.
if ($count == 1) 
{
$row = mysqli_fetch_array($result);
$_SESSION['users'] = array();
$_SESSION['users']['username'] = $row['username'];
$_SESSION['users']['avatar'] = $row['avatar'];
...

I hope this helps.