title: instance of UIViewcontroller in Swift
body: <p>How can i switch one <code>UIViewcontroller</code> to another <code>UIViewController</code> in <code>Swift</code> language? I 'm create a new empty project and and set <code>UINavigationcontroller</code> and not using story board.</p>
  
  <p>For example we use this code in objective c for pushing view controller </p>
  
  <pre><code>MyViewController *controller = [[MyViewController alloc] initWithNibName:@"MyViewController"    bundle:nil];
  [self.navigationController pushViewController:controller animated:YES]
  </code></pre>
  
  <p>What is the alternative in Swift ?</p>
  
  <p>Any help can be appreciated 
  Thanks in advance.  </p>