title: How to get Class object without instance?
body: <p>Is there any way to get the result of:</p>
  
  <pre><code>    NSObject *a = [[NSObject alloc] init];
      [a class];
  </code></pre>
  
  <p>Without instantiating?
  I wish to pass <b>Class</b> object to function as argument, and check it then. Like this:</p>
  
  <pre><code>    - (void) pushControllerOfClass: (Class) aClass
      {
          if([aClass isSubclassOfClass: *what should I write here?*]) {
          ...
          }
      }
  </code></pre>
  
  <p>Intuitively, I've tried to write</p>
  
  <pre><code>        if([aClass isSubclassOfClass: UIViewController]) {
  </code></pre>
  
  <p>But it doesn't work.
  Thx for future response.</p>
  
  <p><strong>Update:</strong>
  Is such a function considered bad in ObjectiveC?
  I've refactored code from Nahavandipoor's book <em>iOS 5 Programming Cookbook</em>. 
  It was like that:</p>
  
  <pre><code>- (void) pushSecondController{
      SecondViewController *secondController = [[SecondViewController alloc]
                                               initWithNibName:nil 
                                               bundle:NULL];
      [self.navigationController pushViewController:secondController animated:YES];
  }
  </code></pre>
  
  <p>As for me, this is kind of bad function:
  It doesn't parametrized when it should be.</p>