title: Comparing an array and getting the difference
body: <p>How would I compare two arrays that might have different lengths and get the difference between each array?</p>
  
  <p><strong>For example:</strong></p>
  
  <pre><code>Cat cat = new Cat();
  Dog dog = new Dog();
  Alligator alligator = new Alligator();
  
  Animal animals[] = { cat, dog };
  Animal animals2[] = { cat, dog, alligator };
  </code></pre>
  
  <p>How would I compare them two arrays and make it return the instance of <code>Alligator</code>?</p>