title: How to get objects for a month in swift
body: <p>I have an array and this array contains <code>Observation</code> type element which has a <code>date</code> property in it.</p>
  
  <p>I just want to get all the elements depending on the month and year. </p>
  
  <p>Suppose if I have a date 01/11/2015, so I want to get all the elements from the <code>observationList</code> which have month 11 and year 2015.</p>
  
  <p>The sample code is as below,</p>
  
  <pre><code>class  Observation
  {
    var date:NSDate = NSDate()
    var value:String = ""
  }
  
  var observationList = [Observation]()
  </code></pre>
  
  <p>suppose that the above <code>observationList</code> has the element then how will I get all the element for e.g. <em>November, 2015?</em></p>