title: Segue to a UINavigation Controller programmatically without storyboards
body: <p>I have code that uses Storyboards for seques, like so:</p>
  
  <pre><code>- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
  {
      if ([segue.identifier isEqualToString:@"ShowDiagnosis"])
      {
          [segue.destinationViewController setHappiness:self.diagnosis];
      }
      ...
  </code></pre>
  
  <p>But I want to do it programmatically. I have myViewController class and when I click on a button I want to animate and push to myUINavigationController.</p>
  
  <p>How is this done programmatically?</p>