title: What is the meaning of "...args" (three dots) in a function definition?
body: <p>It was really confusing for me to read this syntax in Javascript:</p>
  
  <pre><code>router.route('/:id')
  .put((...args) =&gt; controller.update(...args))
  .get((...args) =&gt; controller.findById(...args));
  </code></pre>
  
  <p>What does <strong>...args</strong> mean?</p>