How can I use 'null coalescing operator' together with converting values if they exists?

Question

This is my code

$bookid = (int)$_POST['bookid'] ?? 0;
$userid = (int)$_POST['userid'] ?? 0;
$binding = (int)$_POST['binding'] ?? 0;
$colorpages = (int)$_POST['colorpages'] ?? 0;

and I am getting an error: Undefined index: binding in ... I know I am getting this error because I am using (int) function to a null variable, but how can i fix this? Convert the value to int and still be able to use the coalescing operator if there is not any value. Thanks!

Answer 1

$bookid = (int)($_POST['bookid'] ?? 0);
$userid = (int)($_POST['userid'] ?? 0);
$binding = (int)($_POST['binding'] ?? 0);
$colorpages = (int)($_POST['colorpages'] ?? 0);

So (int) won't have to deal with the null values