title: Null Coalescing for String to Int
body: <p>I want to do a checking on a textbox, if null then assign zero, after that proceed with some calculation. I know there is a null coalescing (??) operator can help me, but I'm not sure is it possible for me to assign int when textbox is empty.</p>
  
  <p>I tried to write something like this, but seems like is an error. </p>
  
  <pre><code>sdowntime = Convert.ToInt32(txtSDown.Text) ?? 0;
  </code></pre>
  
  <p>I get this </p>
  
  <blockquote>
    <p>Error 98  Operator '??' cannot be applied to operands of type 'int' and 'int' </p>
  </blockquote>
  
  <p>Anything I made it wrong or actually I should use another method? Please guide. 
  Thank you very much!</p>