Codeigniter return username based on id - php

Question

I created a helper for returning a user's username if the user's unique id is known.
if ( ! function_exists('get_username'))
{
function get_username($user_id)
{
$ci=& get_instance();
$ci->load->database();
if (empty($user_id))
{
return FALSE;
}
$ci->db->select('username');
$ci->db->where('id', $user_id);
$ci->db->where('activated', 1);
$ci->db->where('banned', 0);
$ci->db->limit(1);
$query = $ci->db->get('users');
if ($query->num_rows() > 0) //if user exists
{
$row = $query->row();
return $row->username;
}
else
{
return FALSE;
}
}
}
This works in my view if for instance I try:
echo get_username($this->uri->segment(3)); //uri segment 3 is a user id.
However want to send the username to my view via controller. I tried the following in my controller:
function write_message($user_id = '') //function parameter is 3rd uri segment
{
$data['username'] = get_username($user_id);
$this->load->view('my_view', $data);
}
Then in my view I have
echo $username which echoes array instead of the username. What am I doing wrong here?

Answer 1

Your criteria should be clear, and the usrname should be unique i think, so...
if ($query->num_rows() == 1) //if user exists, and unique
{
$res = $query->result_array();
return $res[0]['username'];
}
else
{
return FALSE;
}

Answer 2

Upon using <pre>print_r($username)</pre> in my view (as suggested by Alfonso) it was easy to spot the issue, being an identical variable name in my view which was another array. Correct answer goes to anyone that gives a good suggestion/input for my helper or Alfonso if he submits his post as answer.