Integer Not Adding PHP - php

Question

I've got a function on my website so that when people click on a link, they are supposed to have 5 points added to their profile, but that doesn't seem to be working, instead their points just stick to 5.
The following code is what I have used to set up a function:
$points = $user_data['points'];
function pointAdd($user_id, $points) {
$user_id = (int)$user_id;
$pointsPlus = $points += 5;
mysql_query("UPDATE `users` SET `points` = '$pointsPlus' WHERE `user_id` = $user_id");
}
And I have added this to the page, so that when they enter it, the code is put into play:
$target = $_GET['target'];
if(logged_in() === true){
pointAdd($session_user_id, $pointsPlus);
header('Location: ' . $target);
exit();
}
But, when they enter the page, the function doesn't work and the user is just set to 5 points instead of having 5 extra added to their profile.

Answer 1

Your pointsPlus variable that you pass into your function is empty. I don't know where user_data comes from, but the solution is something like this. And also the name 'pointsPlus' is logically incorrect, because there are the base points that the user already has.
$target = $_GET['target'];
if(logged_in() === true){
$points = $user_data['points'];
pointAdd($session_user_id, $points);
header('Location: ' . $target);
exit();
}