title: How to check if an array contains any item of another array
body: <p>Given 2 int arrays e.g, <code>foo</code> and <code>bar</code>, what's the most efficient way to check that the array bar contains at least one item that foo contains. should return true/false.</p>
  
  <p>I'm suspecting nested <code>foreach</code> but just wondering if there's a nicer way?</p>