Using the jQuery $.post function, if you send a null value, it arrives at the server side as "null". Example:

Javascript:

$.post('test.php', { foo : null });

PHP:

var_dump($_POST['foo']); // string(4) "null"

I understand why this is so, but was wondering the best way to work around the limitation? Should you:

1. Loop through all the variables in JS before you send them and replace with an empty string?
2. Interpret "null" as null on the server side?
3. Don't send the variable at all?
4. Something else?