title: Best way to group and sort an array of objects
body: <p>I have the following demo data.</p>
  
  <pre><code>var demoData= [{"EntryGroupDate":"November 2013", 
                  "DisplayName": "Hans Meier (November)", 
                  "EntryGroupDateSort": 11},
                 {"EntryGroupDate":"August 2013", 
                  "DisplayName": "Franz Mueller (August)", 
                  "EntryGroupDateSort": 8},
                 {"EntryGroupDate":"November 2013", 
                  "DisplayName": "Franz Huber (November)", 
                  "EntryGroupDateSort": 11},
                 {"EntryGroupDate":"Juli 2013", 
                  "DisplayName": "Franz Schmidt (Juli)", 
                  "EntryGroupDateSort": 7}
                ];
  </code></pre>
  
  <p>What would be the best way to group them first by <code>EntryGroupDateSort</code> and sort them afterwards by the same criteria. For the output I need all the information of the original array.</p>
  
  <p>I have just fiddled around with UnderscoreJS but did not get the desired result by using the following code.</p>
  
  <pre><code>var myPersons = demoData;
  var groups = _.groupBy(myPersons, "EntryGroupDate");
  console.log(groups);
  groups = _(groups).sortBy(function (item) {
      return item.EntryGroupDateSort;
  });
  console.log(groups);
  </code></pre>
  
  <p>The first console output shows the data in the format I would like to have after sorting the data.</p>
  
  <p>Hopefully someone can point me in the right direction.</p>