title: JavaScript: comma after opening bracket of parameter in syntax example
body: <p>The syntax for methods such as <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf" rel="nofollow">Array.prototype.indexOf()</a> look like this:</p>
  
  <p><code>arr.indexOf(searchElement[, fromIndex = 0])</code></p>
  
  <p>What does <code>[, ...]</code> mean, and why is the comma inside of the brackets?</p>