question.swift

// view contains a label and a button - curious about lines 11 through 14

class ViewController: UIViewController {
  @IBOutlet weak var label: UILabel!
  
  // ...
  
  @IBAction func didPressButton(sender: AnyObject) {
    let date = NSDate()
    
    // what's the difference between doing:
    label.text = "Button pressed at \(date)"
    // versus doing:
    self.label.text = "Button pressed at \(date)"
  }
}

In Objective-C, self would be required to specify that it is a function of the View Controller. In Swift, it isn't necessary to start with self (They do the same thing, but the version without self is preferred).