title: What does ?? operator means in C#?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/446835/what-do-two-question-marks-together-mean-in-c">What do two question marks together mean in C#?</a>  </p>
  </blockquote>
  
  
  
  <p>Hi, I was looking for some trainings of MVC 2 in C# and I found this sintax:</p>
  
  <pre><code>ViewData["something"] = something ?? true;
  </code></pre>
  
  <p>So, what is that '??' means ?.</p>