title: Add if not nil?
body: <p>How do I write a one-liner for the following?</p>
  
  <pre><code>x = y + (z if != nil)
  </code></pre>
  
  <p>I tried a few different things and also searched, but can't seem to find anything that's specific to this. </p>
  
  <p>I tried:</p>
  
  <pre><code>x = y + z? z : 0
  </code></pre>
  
  <p>but that didn't work (syntax?) and even if it did, it feels sloppy.</p>