Just a short one today, because I’m really busy (un)fortunately.

You can take out and check each argument at a time:

  $search = isset($_GET['search']) ? $_GET['search'] : null;
  $page = isset($_GET['page']) ? $_GET['page'] : 1;
  $limit = isset($_GET['limit']) ? $_GET['limit'] : 15;
  // etc

But to do it in one go, just do:

  $args = $_GET + array('search'=>null, 'page'=>1, 'limit'=>15);

Note that in some cases it is important to filter your input, that is not done here.