title: Checking for nil string before concatenating
body: <p>This question is similar to a LOT of questions, but in no such way is it anything of a duplicate. This question is about string concatenation and writing better code less than it is for checking nil/zero.</p>
  
  <p>Currently I have:</p>
  
  <pre><code>file.puts "cn: " + (var1.nil? ? "UNKNOWN" : var1)
  </code></pre>
  
  <p>Which works fine, but doesn't look good. What is a better way to write this in ruby so that I am checking for nil and not concatenating it</p>