title: Pick a random element from an array
body: <p>Suppose I have an array and I want to pick one element at random.</p>
  
  <p>What would be the simplest way to do this?</p>
  
  <p>The obvious way would be <code>array[random index]</code>. But perhaps there is something like ruby's <code>array.sample</code>? Or if not could such a method be created by using an extension?</p>