PHP undefined key and variable

Question

I followed your tutorial here about user registration using PHP and MySQL here: https://youtu.be/qjwc8ScTHnY

However, Im getting these errors:

Warning: Undefined array key "username" in C:\xampp\htdocs\Sublime\Web1\server.php on line 17

Warning: Undefined array key "email" in C:\xampp\htdocs\Sublime\Web1\server.php on line 18

Warning: Undefined array key "password" in C:\xampp\htdocs\Sublime\Web1\server.php on line 19

Warning: Undefined array key "confirmpassword" in C:\xampp\htdocs\Sublime\Web1\server.php on line 20


This are those line:

$username = mysqli_real_escape_string($db, $_POST['username']);
$email = mysqli_real_escape_string($db, $_POST['email']);
$password = mysqli_real_escape_string($db, $_POST['password']);
$confirmpassword = mysqli_real_escape_string($db, $_POST['confirmpassword']);

I did a work around by doing this:

if (isset($_POST['username']) || isset($_POST['email']) || isset($_POST['password']) || isset($_POST['confirmpassword'])) {

    $username = mysqli_real_escape_string($db, $_POST['username']);
    $email = mysqli_real_escape_string($db, $_POST['email']);
    $password = mysqli_real_escape_string($db, $_POST['password']);
    $confirmpassword = mysqli_real_escape_string($db, $_POST['confirmpassword']);
}

But now Im getting undefined variable at line 30 which are $password and $confirmpassword which is the line:

if ($password != $confirmpassword) {array_push($errors, "Password must be the same");};

Please help! And why am I getting these errors? Thanks!

Answer 1

Hi, @Dann,

If you are using some variable then please check if its set or not

<?=$user_name;?> you need to chnage to <?=(isset($user_name)?$user_name:""?> and same for ot