Use of unresolved identifier 'showAlert' Swift

Question

I'm new in Swift and I'm stacked with this piece of code and every time it return to me "Use of unresolved identifier 'showAlert' for User enter region and User exit region:

    func setupData() {
        // 1. check if system can monitor regions
        if CLLocationManager.isMonitoringAvailable(for: CLCircularRegion.self) {

            // 2. region data
            let title = "Primo punto"
            let coordinate = CLLocationCoordinate2DMake(38.121973, 13.360855)
            let regionRadius = 300.0

            // 3. setup region
            let region = CLCircularRegion(center: CLLocationCoordinate2D(latitude: coordinate.latitude,
                                                                         longitude: coordinate.longitude), radius: regionRadius, identifier: title)
            locationManager.startMonitoring(for: region)

            // 4. setup annotation
            let restaurantAnnotation = MKPointAnnotation()
            restaurantAnnotation.coordinate = coordinate;
            restaurantAnnotation.title = "\(title)";
            mapView.addAnnotation(restaurantAnnotation)

            // 5. setup circle
            let circle = MKCircle(center: coordinate, radius: regionRadius)
            mapView.add(circle)
        }
        else {
            print("System can't track regions")
        }
    }

    // 6. draw circle
    func mapView(mapView: MKMapView, rendererForOverlay overlay: MKOverlay) -> MKOverlayRenderer {
        let circleRenderer = MKCircleRenderer(overlay: overlay)
        circleRenderer.strokeColor = UIColor.red
        circleRenderer.lineWidth = 1.0
        return circleRenderer
    }

    // 1. user enter region
    func locationManager(manager: CLLocationManager, didEnterRegion region: CLRegion) {
        showAlert("enter \(region.identifier)")
    }

    // 2. user exit region
    @nonobjc func locationManager(manager: CLLocationManager, didExitRegion region: CLRegion) {
        showAlert("exit \(region.identifier)")
    }
}

Answer 1

I don't know if you have a 'showAlert()' function but if you are trying to alert the user then you can do it like this:

//Create alert
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)

// Add action buttons to the alert
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))

// Present the alert to the view
self.present(alert, animated: true, completion: nil)

if you want to make it as a function then just create one called show alerts and add your own parameters to the function. Like this:

func showAlert(Title: String, Message: String) {
    let alert = UIAlertController(title: Title, message: Message, preferredStyle: UIAlertControllerStyle.alert)
    alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))
    self.present(alert, animated: true, completion: nil)
}