title: Sorting array of objects by field
body: <p>I have objects</p>
  
  <pre><code>Person{
      String name;  
      int age;
      float gradeAverage;
      }
  </code></pre>
  
  <p>Is there an easy way to sort </p>
  
  <pre><code>Person[] ArrayOfPersons
  </code></pre>
  
  <p>by age?</p>
  
  <p>Do I have to use Comparable or Comparator? I don't fully understand them.</p>