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

if (is_int($_GET['category']) and $_GET['category'] > 0 and $_GET['category'] <= 120)

This will check if the number is greater than zero and smaller or equal to 120.