UISegmentedControl deselect (make none of the segments selected)

The right way to do this is:

[menu setSelectedSegmentIndex:UISegmentedControlNoSegment];

Edit:

Swift 5:

menu.selectedSegmentIndex = UISegmentedControl.noSegment

Setting the segmentedControl to .momentary = YES changes the way the user can interact with the segmentedControl. If you want to have nothing selected initially when the page loads but have segmentedControl behave the same after a selection is made by the user then you will want something more like this:

Swift 4 solution:

 @IBOutlet weak var segmentedControl: UISegmentedControl!

 self.segmentedControl.selectedSegmentIndex = UISegmentedControlNoSegment

Swift 5.1:

 self.segmentedControl.selectedSegmentIndex = UISegmentedControl.noSegment

I guess you try to create a momentary selection in segmented control. In interface builder set the segmentedcontrol to momentary. Or in code you can do:

menu.momentary = YES;

swift 4

@IBOutlet weak var segmentControl: UISegmentedControl! {
    didSet {
        segmentControl.selectedSegmentIndex = UISegmentedControl.noSegment
    }
}

I did class which supports this kind of interaction:

class UIDeselectableSegmentedControl: UISegmentedControl {

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        let previousSelectedSegmentIndex = self.selectedSegmentIndex

        super.touchesEnded(touches, with: event)

        if previousSelectedSegmentIndex == self.selectedSegmentIndex {

            self.selectedSegmentIndex = UISegmentedControl.noSegment
            let touch = touches.first!
            let touchLocation = touch.location(in: self)
            if bounds.contains(touchLocation) {
                self.sendActions(for: .valueChanged)
            }
        }
    }
}

The main advantage of that is that you just need to modify which class the Storyboard/Xib/ViewCode is using and this will work like a charm ;]