title: Multi null checking
body: <p>Is there any more efficient,cleaner and shorter form for following:</p>
  
  <pre><code>if($x==null or $y==null or $z==null or $w==null) return true;
  </code></pre>
  
  <p><strong>In general how can I also get name of null variables?</strong></p>
  
  <pre><code>function any_null(array $a){
      foreach($a as $v) if ($v==null) return //variable name;
      return false;
  }
  var_dump(any_null(array($x,$y,$z,$w)));
  </code></pre>