How to add value inside a loop - codeigniter-3

Question

i have this code that suppose to sum up the count from a specific
function but all i do get is different
the printed value suppose to be 8 but am get 4 4 4 4 instead
i have Tried any possible way to get it work but its difficult for me, every suggestion,ideal, recommendation is highly needed.
, please what must i do? or what am not doing
here is the Code
public function upgrade_admin_to_prime(){
//get the admins
$admin_users =$this->get_admin_user();
foreach($admin_users as $row){
$admin_username =$row['username'];
//check if my downline that is my ingress downline is upto 2
$downline_count =$this->count_if_downline_is_complete($admin_username);
if($downline_count == 2){
//get my downline user
$downline_users =$this->list_my_downline($admin_username);
foreach($downline_users as $row){
$downline_username =$row['downline_username'];
//check if user downline count is 4
//$downline_count2 ='';
$downline_count2 =$this->count_if_downline_is_complete($downline_username);
$downline_count2 =$downline_count2+$downline_count2;
if($downline_count2 == 4){
$downline_users3 == // array of 4 users 'favor','kane','samson','fish'
foreach($downline_users3 as $row){
$downline_username3 =$row['downline_username'];
$downline_count3 =2;
echo $downline_count3 =$downline_count3+$downline_count3;
if($downline_count3 == 8){
echo "Yess oo";
}else{
echo "nope";
}
}
}else{
echo '2nd Generation Downline user count is not complete yet'.br();
}
}
}else{
echo 'your count is not complete yet'.br();
}
}
}
i want this code here to Output 8 for me but its giving me 4 4 4 4
$downline_count3 =2;
echo $downline_count3 =$downline_count3+$downline_count3;
if($downline_count3 == 8){
echo "Yes oo";
}else{
echo "nope";
}