title: group array values by ID
body: <p>I'm trying to combine arrays by the id and then sort by the date. The output array is: </p>
  
  <pre><code>    Array
  (
      [abc] =&gt; Array
          (
              [0] =&gt; Array
                  (
                      [id] =&gt; 7
                      [date] =&gt; 2018-03-28
                      [message] =&gt; test1
                  )
  
              [1] =&gt; Array
                  (
                      [id] =&gt; 81
                      [date] =&gt; 2018-03-27
                      [message] =&gt; test5
                  )
  
              [2] =&gt; Array
                  (
                      [id] =&gt; 7
                      [date] =&gt; 2018-03-27
                      [message] =&gt; test9
                  )
              [3] =&gt; Array
                  (
                      [id] =&gt; 5
                      [date] =&gt; 2018-03-25
                      [message] =&gt; test
                  )
  
          )
  
  )
  </code></pre>
  
  <p>How do I show just the unique ID's sorted by date so that it displays:</p>
  
  <pre><code>id: 7 - 2018-03-28
  id: 81 - 2018-03-27
  id: 5 - 2018-03-25
  </code></pre>