title: How to access the iOS system font programmatically
body: <p>I am trying to change the font size of the title of a navigation bar. I know I can set its attributes using:</p>
  
  <pre><code>var attributes = [ NSForegroundColorAttributeName: UIColor.blackColor(), NSFontAttributeName: UIFont(name: "the font name", size: 18)! ]
  </code></pre>
  
  <p>...</p>
  
  <pre><code> self.navigationController?.navigationBar.titleTextAttributes = attributes
  </code></pre>
  
  <p>What I cannot seem to find is the correct 'System' font name.</p>
  
  <p>I was after the default, a.k.a System, font name. I tried printing all the available fonts only to discover it does not belong to a family and does not seem to have an explicit name.</p>