title: Add several attributes to a NSMutableAttributedString
body: <p>I'm trying to add several attributes to a NSMutableAttributedString; i tried this:</p>
  
  <pre><code>let stringNumero: NSString = "\(squadra.cori.count)" //= two-digit number
  var stringNumeroMutable = NSMutableAttributedString()
  stringNumeroMutable = NSMutableAttributedString(string: stringNumero as! String, attributes: [NSFontAttributeName: UIFont(name: "Noteworthy-Light", size: 9)!,
                                                                                                    NSForegroundColorAttributeName: UIColor(red: 110/255.0, green: 183/255.0, blue: 93/255.0, alpha: 1.0)])
  cell.numeroCori.attributedText = stringNumeroMutable
  </code></pre>
  
  <p>now I'd like to add an other attributes and i'm going uso this code:</p>
  
  <pre><code>stringNumeroMutable.addAttribute(NSFontAttributeName, value: UIFont.boldSystemFontOfSize(8), range: NSRange(location: 0, length: 1))
  </code></pre>
  
  <p>but I'm incurring in a problem:</p>
  
  <p><a href="https://i.stack.imgur.com/6LuA1.png" rel="noreferrer"><img src="https://i.stack.imgur.com/6LuA1.png" alt="enter image description here"></a></p>
  
  <p>as you see, the bold effect is attributed only to the first digit and the previous attributed (such as the font) disappear. I think the the second NSFontAttributedName subscribe the previous one, so is there any way to set both font and bold?
  Thanks a lot!!!</p>
  
  <p>Edit: as suggested i tried to recall the method like this:</p>
  
  <pre><code>let stringNumero: NSString = "\(squadra.cori.count)" //= two-digit number
  var stringNumeroMutable = NSMutableAttributedString()
  stringNumeroMutable = NSMutableAttributedString(string: stringNumero as! String, attributes: [NSFontAttributeName: UIFont(name: "Noteworthy-Light", size: 9)!,
                                                                                                    NSForegroundColorAttributeName: UIColor(red: 110/255.0, green: 183/255.0, blue: 93/255.0, alpha: 1.0)])
  cell.numeroCori.attributedText = stringNumeroMutable
  
  stringNumeroMutable.addAttribute(NSFontAttributeName, value: UIFont.boldSystemFontOfSize(9), range: NSRange(location: 0, length: stringNumeroMutable.length))
  
  cell.numeroCori.atributedText = stringNumeroMutable
  </code></pre>
  
  <p>but the second call overwrite the first one (so the number loose the attributed font). How to solve this?</p>
  
  <p><a href="https://i.stack.imgur.com/SYq5G.png" rel="noreferrer"><img src="https://i.stack.imgur.com/SYq5G.png" alt="enter image description here"></a></p>