How to "properly" handle $_GET variables in PHP?

Question

Currently, I have the following code:

if(isset($_GET['mid']) && !empty($_GET['mid'])) {
    $mid = $_GET['mid'];

    if(is_numeric($mid) && $mid > 0) {
        if(isset($_GET['op']) && !empty($_GET['op'])) {
            $op = $_GET['op'];

            if($op == 'info') {
            }

            if($op == 'cast') {
            }
        }
    }
}

But I think it's too "complex" with if statements inside if statements, etc...

Would you handle it differently? How would you make it simpler?

Answer 1

I would use filter_input with the FILTER_SANITIZE_NUMBER_FLOAT filter for mid. Something like that :

$mid = filter_input(INPUT_GET, 'mid', FILTER_SANITIZE_NUMBER_FLOAT);
$op = filter_input(INPUT_GET, 'op');
if($mid > 0){
  switch($op){
    case 'info':
      // Some code
      break;
    case 'cast':
      // Some more code
      break;
    default:
      break;
  }
}