title: Ruby - each starting offset
body: <p>How do I set a starting offset for <code>each</code> loop in ruby? 
  I want the loop to begin from <code>a[3]</code> instead of <code>a[0]</code>. How do I set that?  </p>
  
  <pre><code>a = [ab, cd, ef, gh, hi, jk]
  
  a.each do |i|
  #some stuff
  end
  </code></pre>