title: What's the point of "As" keyword in C#
body: <p>From the docs: </p>
  
  <blockquote>
    <p>The as operator is like a cast except that it yields null on conversion failure instead of raising an exception. More formally, an expression of the form:</p>
  
  <pre><code>   expression as type
  </code></pre>
    
    <p>is equivalent to:</p>
  
  <pre><code>  expression is type ? (type)expression : (type) null
  </code></pre>
    
    <p>except that expression is evaluated only once.</p>
  </blockquote>
  
  <p>So why wouldn't you choose to either do it one way or the other.  Why have two systems of casting?</p>