Ok so, I'm not at all good at coding but I'm working on a uni assignment and this is throwing me off. Basically, what I'm trying to do is create a payroll system that takes data from 2 different json files (one for tax and one for employee info) and calculates their take-home monthly wage by deducting tax from annual salary.

I don't know if you'll be able to help based on the snippet but I've finally got the code to read both json files but it's throwing this warning:

Warning: foreach() argument must be of type array|object, null given in C:\xampp\htdocs\dap405\payroll\payroll.php on line 7

on this bit of code:

foreach ($taxtables as $band) {
if ($salary > $band ['minsalary'] && $salary < $band ['maxsalary']) {
return $band ['id'];
    }

and I don't know what I've done wrong. Any help?