title: Does viewDidload method call again on going back to a screen in navigation controller?
body: <p>I am using navigation controller. I have pushed two viewcontroller to navigation stack. When I am coming back to <strong>viewcontroller1</strong> from <strong>viewcontroller2</strong> using back button of navigation bar then <code>viewdidload</code> method of <strong>viewcontroller1</strong> is called again.But as much as I know viewdidload is called only once at loading time. So why is this happening? Please tell me.</p>
  
  <p>Thanks!!</p>