如果任何这些变量为空，则运行语句

So I have this:

$title = $_POST['title'];
$keywords = $_POST['keywords'];
$purpose = $_POST['purpose'];
$special = $_POST['special'];
$length = $_POST['length'];
$email = $_POST['email'];

I want to run a statement if any of these variables is empty. I know I can run an if statement checking if any of them are empty but is there a simpler way or perhaps a function that could do it with less code?

I could do this:

if($title == '' || $keywords == '' || etc etc...

But is there a method to do it with less code? That just seems a bit clunky.

Thanks!

$vars=array('title','keywords','purpose','special','length','email');

$allfilled=true;
foreach ($vars as $var) {
  $$var=$_POST[$var];
  if ($$var == '') $allfilled=false;
}

if (!$allfilled) ...

For fix it i usually use this solution.

$keys = array('title','keywords','any_other_key');
$isError = false;
$data = array();
foreach($keys as $key) {
    if (!isset($_POST[$key]) || $_POST[$key] == '') { 
        $isError = $key;
        break;
    } else {
        $data[$key] = strip_tags($_POST[$key]);
    }
}

if ($isError !== false) {
    // Error. Some fields are not filled!
    // Error field are in $isError variable;
}