title: When is the comma operator useful?
body: <p>I read <a href="https://stackoverflow.com/questions/3561043/javascript-syntax-what-comma-means">this</a> question about the "comma operator" in expressions (<code>,</code>) and the <a href="https://developer.mozilla.org/en/JavaScript/Reference/Operators/Special_Operators/Comma_Operator" rel="noreferrer">MDN docs</a> about it, but I can't think of a scenario where it is useful. </p>
  
  <p>So, when is the comma operator useful?</p>