title: Ruby (Rails): remove whitespace from each array item
body: <p><a href="http://granth.ca/2006/02/strip-whitespace" rel="nofollow noreferrer">I found this code</a>:</p>
  
  <pre><code>.each_key {|a| self[a].strip! if self[a].respond_to? :strip! }
  </code></pre>
  
  <p>...but it is for a hash, whereas I am trying to do the same with an array.</p>