Fatal error: Call to undefined function updateRows() - function

Question

I got this error:
Fatal error: Call to undefined function updateRows()
but I have defined updateRows(), so what is wrong?
Here is my code:
<?php
if ($this->num_rows > 0) {
$i = 0;
while ($row = $stmt->fetchObject()) {
$appleIDS[$i] = array(
$row->id,
$row->pass,
$row->en_b_y,
$row->en_b_m,
$row->en_b_d,
$row->sqa1,
$row->sqa2,
$row->sqa3
);
$i++;
}
updateRows($this->pre_head, $head);
killTheConnection();
return $appleIDS;
}
killTheConnection();
return $check;
}
function updateRows($pre_head, $head) // here is my function
{
$this->mysqli_connet();
try {
$sql = "UPDATE appleid " . "SET taken = 'yes'" . "," . "taken_time=now()" . "WHERE num>=$pre_head AND num<=$head;";
$stmt = $GLOBALS['$connection']->prepare($sql);
$stmt->execute();
echo $stmt->rowCount();
}
catch (PDOException $e) {
echo $sql . "<br>" . $e->getMessage();
}
killTheConnection();
}
?>