title: Filter two arrays Swift
body: <p>I have one empty array and two arrays with data</p>
  
  <pre><code>var resultsArray = [String]()
  
  var array1 = ["1","2","2","3","4"]
  var array2 = ["1","2","2","3","4","5","6"]
  </code></pre>
  
  <p>My goal is to append the <code>resultsArray</code> with the elements from <code>array2</code> that don't match <code>array1</code> ("5" and "6" in the example). </p>
  
  <p>What's the subtlest way to do so?</p>
  
  <p>Thank you.</p>