title: NodeJS JSON Array filtering
body: <p>I have used Node to retrieve a set of results from SQL and they're returned like this;</p>
  
  <pre><code>[
     {
     "event_id": 111111,
     "date_time": "2012-11-16T01:59:07.000Z",
     "agent_addr": "127.0.0.1",
     "priority": 6,
     "message": "aaaaaaaaa",
     "up_time": 9015040,
     "hostname": "bbbbbbb",
     "context": "ccccccc"
  },
     {
     "event_id": 111112,
     "date_time": "2012-11-16T01:59:07.000Z",
     "agent_addr": "127.0.0.1",
     "priority": 6,
     "message": "aaaaaaaaa",
     "up_time": 9015040,
     "hostname": "bbbbbbb",
     "context": "ddddddd"
  },
  ]
  </code></pre>
  
  <p>There are usually a lot of entries in the array and I need to efficiently filter the array to show only the entries that have a context of "ccccccc". I've tried a for loop, but it's incredibly slow.</p>
  
  <p>Any suggesstions?</p>