title: VueX Getter to filter unique id's from array
body: <p>I want to filter an array (that contains objects), to grab each message that contains a unique <code>correspondence_id</code>. </p>
  
  <p>**Store contains 'messages' (with this structure):
  <a href="https://i.stack.imgur.com/1H33F.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1H33F.png" alt="enter image description here"></a></p>
  
  <p><strong>Getters</strong> where I want to filter it.</p>
  
  <pre><code>getCorrespondedUsers: (state) =&gt; {
          return state.messages.unique
      }
  </code></pre>
  
  <p>The messages all contain a <code>correspondence_id</code>, however now I can only grab all the messages, but I want to just grab unique people. The purpose of this is that I have messages, but on the left I want to display each person that I've messaged (but I'm not sure how I can only display each person once).</p>
  
  <p>How can I filter my messages to just return each message with a unique <code>correspondence_id</code>?</p>