Nullable int as action parameter
<p>in this Code</p>

<pre><code>public ActionResult Index(int? id)
{
  return View();
}
</code></pre>

<p>What does the <code>int? id</code> do? </p>

<p>Can we write it in this format also?</p>

<pre><code>public ActionResult Index()
{
  int id;
  return View();
}
</code></pre>