title: Convert swift arrays into JSON object
body: <p>I have two arrays :</p>
  
  <pre><code>let value = [41, 42, 45] ...
  let date = [NSDate1, NSDate2, NSDate3] ...
  </code></pre>
  
  <p>I need to save the data as a json object onto our mongodb on the server. I tested with a sample object formatted as below and it worked as expected.  How can I reformat my arrays into this format efficiently in swift/objective c?</p>
  
  <pre><code>let jsonObject = [
  ["date" : "2014/01/01", "value" : "41"],
  ["date" : "2014/01/02", "value" : "42"],
  ["date" : "2014/01/03", "value" : "45"]]
  </code></pre>
  
  <p>Any help would be very much appreciated ! Thank you !</p>