title: Convert an array of Ints to a comma separated string
body: <p>I know that if I want to convert an array of <code>Int</code>s to a <code>String</code>, I do this:</p>
  
  <pre><code>[0,1,1,0].map{"\($0)"}.reduce(""){$0+$1}
  </code></pre>
  
  <p>but I cannot figure out how would I convert an array of <code>Int</code>s to a comma separated <code>String</code></p>