How can I limit the max value of number?

Question

I want to secure my page by checking if the value is digital (0,1,2,3) and if it is in the range from 0 to 120. I think ctype_digit function limits numbers, so

Answer 1

Not an answer, but here's why what you had wouldn't work:

if (!ctype_digit($_GET['category'] > 120) ?
                 ^^^^^^^^^^^^^^^^^^^^^^^

The indicated part is inside the ctype call. So first PHP will check if the GET value is greater than 120, turning that into a boolean true/false. THEN the ctype is applied, which will always be false, as a boolean value is not a digit.