foreach loop populate array for call_user_func_array

I am using a foreach loop to populate an array with parameter types and parameter values before it inserts into the database. Everything works fine and posts to the db, but I can’t figure out why it sends both values as the same when they are added (as a reference) to the array. I have tired calling unset(); but it doesn’t do the trick.

function insertUsers($db, $sql, $vals){
     $stmt= $db->prepare($sql);
     $types='';
     $types= $types ?: str_repeat("s", count($vals));
     $inputArray [] = &$types;

     foreach($vals as $key=>$value){
         $inputArray[]= &$value;
         unset($key);
     }
     print_r($inputArray);

     call_user_func_array(array($stmt, 'bind_param'), $inputArray);
     $stmt->execute();
     $stmt->close();
 }

The result ends being:

Array
(
  [0] => ss
  [1] => tyuty (note this value changes to the last value)
  [2] => tyuty 
)

Answer

You need to remove & from there inside foreach();-

foreach($vals as $key=>&$value){ // put & here
  $inputArray[]= $value; // remove & from here and unset() not needed actually
}

And Add & inside function argument too:-

function insertUsers($db, $sql, &$vals){