Checking if an Object is null at the same time as a value of one of it's fields
<p>Which of these would be correct?</p>

<pre><code>if(dialog != null &amp;&amp; dialog.isShowing){}

if(dialog.isShowing &amp;&amp; dialog != null){}

if(dialog != null){
   if(dialog.isShowing){}
}
</code></pre>
