php validate integer

Question

I`m wonder why this not working

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

Answer 1

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.
}