title: Array include any value from another array?
body: <p>What's the most efficient way to test if an array contains any element from a second array?</p>
  
  <p>Two examples below, attempting to answer the question does <code>foods</code> contain any element from <code>cheeses</code>:</p>
  
  <pre><code>cheeses = %w(chedder stilton brie mozzarella feta haloumi reblochon)
  foods = %w(pizza feta foods bread biscuits yoghurt bacon)
  
  puts cheeses.collect{|c| foods.include?(c)}.include?(true)
  
  puts (cheeses - foods).size &lt; cheeses.size
  </code></pre>