title: Get array difference between multiple arrays of different sizes
body: <p>Been going around in circles with this for a while.</p>
  <p>For example let's say I have different times slots stored as this</p>
  <pre><code>let timechunks1 = [[&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot;], [&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot;], [&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot;, &quot;12:00&quot;]] 
  let timechunks2 = [[&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot;], [&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot;], [&quot;09:00&quot;, &quot;10:00&quot;]]
  
  
   for (let i=0; i&lt; timechunks.length; i++) {
   differences.push(_.difference(timechunks[0], timechunks[i]))      
  }
  </code></pre>
  <p>Would need to extract 12:00 since it doesn't appear in others. Closest I got was with underscore _difference but alas it's not doing what I expected.</p>
  <p>For timechunks1 I'm looking to return &quot;12:00&quot;
  For timechunks2 I'm looking for a way to return &quot;11:00&quot;</p>
  <p>Added another example</p>
  <pre><code>[
  [&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot; ,&quot;13:00&quot;],
  [&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot;, &quot;13:00&quot;], 
  [&quot;09:00&quot;, &quot;10:00&quot;, &quot;11:00&quot;, &quot;12:00&quot;]
  ]  
  </code></pre>
  <p>for which it would return [&quot;13:00&quot;, &quot;12:00&quot;]</p>