php validate integer

Question

I`m wonder why this not working

    echo gettype($_GET['id']); //returns string
  if(is_int($_GET['id']))
  {
   echo 'Integer';
  }

How to validate data passing from GET/POST if it is integer ?

Answer 1

Can use

$validatedValue = filter_input(INPUT_GET, 'id', FILTER_VALIDATE_INT);

See http://php.net/filter_input and related functions.

Answer 2

The manual says:

To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric().

Alternative you can use the regex based test as:

if(preg_match('/^\d+$/',$_GET['id'])) {
  // valid input.
} else {
  // invalid input.
}