how to detect Segment controller if enabled or not?

Question

I want to make the segment controller must be selected by user but i don't know how to detect if he choose a button on segment controller or not?

I'm trying to write:

if ( segmentbtn != nil)
{
  Println(" You must select!")
}

but isn't working, i'm using Xcode on swift language.

Answer 1

@IBOutlet weak var segmentbtn: UISegmentedControl!

@IBAction func indexChanged(sender: UISegmentedControl) {
    switch segmentbtn.selectedSegmentIndex {
    case 0:
        println("button 1 is selected")
    case 1:
        println("button 2 is selected")
    default:
        break;
    }
}