Having trouble setting user metadata on wordpress init hook - wordpress

Question

I want to insert some user meta data to determine if a user has logged in before or not - with the intention of showing them a welcome screen if they havent.
I've google searched all these functions but they just don't seem to be working for me.
Here is my code...
add_action('init', function() {
$user_ID = get_current_user_id();
$has_visited = get_user_meta($userID, 'has_visited');
//check if has_visited key exists - if it doesn't, user's first visit
if(!$has_visited) {
//set the has_visited key
update_user_meta($user_ID, 'has_visited', 1);
echo 'user has not logged in before';
exit;
}
else { echo 'user has logged in before'; exit; }
});
Do these functions work on the init hook. I need them to so I can redirect the user to another page if it is their first visit.
Thanks in advance for your help and wisdom.

Answer 1

Because you have a typo here:
$has_visited = get_user_meta($userID, 'has_visited');
But, you sad this:
$user_ID = get_current_user_id();
So $user_ID and $userID is not the same.
Anyway, first you need to create another condition, to check, is the user logged in, because if not, then there will be no user ID.
So your complete code should be like this:
add_action('init', function() {
if (is_user_logged_in()) { //Added this
$user_ID = get_current_user_id();
$has_visited = get_user_meta($user_ID, 'has_visited', true); //Fixed this
//check if has_visited key exists - if it doesn't, user's first visit
if (!$has_visited) {
//set the has_visited key
update_user_meta($user_ID, 'has_visited', 1);
echo 'user has not logged in before';
exit;
} else {
echo 'user has logged in before';
exit;
}
}
echo "User not logged in";
});