title: How to find the sum of an array of numbers
body: <p>Given an array <code>[1, 2, 3, 4]</code>, how can I find the sum of its elements? (In this case, the sum would be <code>10</code>.)</p>
  
  <p>I thought <a href="http://api.jquery.com/jquery.each/" rel="noreferrer"><code>$.each</code></a> might be useful, but I'm not sure how to implement it.</p>