title: .ToString(), (string), or as String. When to use what?
body: <p>I ran into a bug that was bothering me.  I had JObject that I thought would be fine with </p>
  
  <pre><code>obj["role"].ToString()
  </code></pre>
  
  <p>The string was there and everything.  A final resort was to change to a  </p>
  
  <pre><code>(string)obj["role"] 
  </code></pre>
  
  <p>just to see what happens and it works.  My question is how do I know when to use a .ToString() as opposed to a (string) as opposed to an "as String".</p>