var empty = true;
$('input[type="text"]').each(function() {
if ($(this).val() != "") {
empty = false;
return false;
}
});
This should look all the input and set the empty var to false, if at least one is not empty.
EDIT:
To match the OP edit request, this can be used to filter input based on name substring.
$('input[name*="denominationcomune_"]').each(...