PHP: a short cut for isset and !empty?

Question

I wonder if there any better ideas to solve the problem below,

I have a form with a number of input fields, such as,

Answer 1

+1 for array_merge() but I think that nevertheless short form for:

if (isset($_POST['some_var']) and !empty($_POST['some_var'])) $some_var = $_POST['some_var'];
else $some_var = NULL;

should be:

$some_var = $_POST['some_var'] ? $_POST['some_var'] : NULL;

yes, it causes "undefined index" notice, but it checks for both existance and emptiness

EDIT: and returns NULL of course, as OP asked.

During a small research, I've found an interesting "Control Flow Function" for this case, I've never used before: NULLIF()

So you can perform this task without PHP. Just wrap all variables in it:

NULLIF('".$_REQUEST['some_var']."', '')

in your query instead of '".$_REQUEST['some_var']."'

If variable is empty or doesn't exist it will be NULLIF('', '') as far as '' == '' it will return NULL. Otherwise it will return first arg == your variable.