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.

Answer 2

I am adding this as some people might stumble here on the search for a way to this task based on the topic of your question.
Sometimes you just want to "limit the max value of a numeric variable".

$val=($val <= 120)?$val:120;

That's the best way I found within one line (a combination of min() and max() can do the same but it's much more calculation intense) If the $val is larger than 120 it will be trimmed to 120, otherwise the original value is used.

Answer 3

if (!ctype_digit($_GET['category']) || $_GET['category'] > 120) die('')

Basically this says "If it's not a number or if it's larger than 120, stop"