title: Difference between Year and yearForWeekOfYear - iOS (NSDateComponents)
body: <p>While working on NSDateComponents I come to know one property which I have never used.</p>
  
  <p>I have try to look in apple document as well but didn't get proper answer.
  Apple says,</p>
  
  <pre><code>Declaration
  OBJECTIVE-C
  
      @property NSInteger yearForWeekOfYear
  
  Discussion
  
  This value is interpreted in the context of the calendar with which it is used
  </code></pre>
  
  <p>Does anybody knows exactly what this property do ?
  e.g.</p>
  
  <pre><code>- Year property will return year value.
  - Day property will rerun day value
  - MonthOfYear property will return month number of particular year
  - WeekOfYear will return Week number of particular year
  - yearForWeekOfYear will return ????? (Can anybody give simple example as well so I can easily understand ) 
  </code></pre>