Change password for logged in user (codeigniter) - codeigniter

Question

Is there any solution how to make change password for logged in user? i want to make a change password for logged in user, the code i made only change user password with user id number 1. it doesn't change for logged in user. so any idea?
this is my controller:
public function update(){
$this->form_validation->set_rules('password', 'Current Password', 'required|alpha_numeric|min_length[6]|max_length[20]');
$this->form_validation->set_rules('newpass', 'New Password', 'required|alpha_numeric|min_length[6]|max_length[20]');
$this->form_validation->set_rules('confpassword', 'Confirm Password', 'required|alpha_numeric|min_length[6]|max_length[20]');
if($this->form_validation->run()){
$cur_password = $this->input->post('password');
$new_password = $this->input->post('newpass');
$conf_password = $this->input->post('confpassword');
$this->load->model('queries');
$userid = '1';
$passwd = $this->queries->getCurrPassword($userid);
if($passwd->password == $cur_password){
if($new_password == $conf_password){
if($this->queries->updatePassword($new_password, $userid)){
echo 'Password updated successfully';
}
else{
echo 'Failed to update password';
}
}
else{
echo 'New password & Confirm password is not matching';
}
}
else{
echo'Sorry! Current password is not matching';
}
}
else{
echo validation_errors();
}
This is my model:
public function getCurrPassword($userid){
$query = $this->db->where(['id'=>$userid])
->get('users');
if($query->num_rows() > 0){
return $query->row();
} }
public function updatePassword($new_password, $userid){
$data = array(
'password'=> $new_password
);
return $this->db->where('id', $userid)
->update('users', $data); }

Answer 1

You can initialize a session when the user logs in to the system at the beginning, and store the information of the user in that session, like this:
function login() {
$query = $this->db->select(*)
->from('table_name')
->where('your parameters....');
return $query->row();
}
function index() {
$userid = $this->login()->id; //id of the user which is currently logged IN
$this->session->set_userdata('current_userId', $userid);
}
You have now stored the id of currently logged IN user in the session. You can access the id by $this->session->userdata('current_userId');. Replace your $userid = '1' by the session data. Also, you will have to load the session library in order to do so.