fatal error: unexpectedly found nil while unwrapping an Optional value while printing on UILabel

Question

I'm trying to display the users current location and calculate the distance he traveled and i'm getting error at displaying it on distance1.text, can somebody please help me. Thanks in advance and I'm very new to iOS app development, currently using swift3

import UIKit
import MapKit
import CoreLocation

class MapView1: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {

    @IBOutlet weak var mapView: MKMapView!
    @IBOutlet weak var distance1: UILabel!

    let locationManager = CLLocationManager()

    var startLocation:CLLocation!
    var lastLocation: CLLocation!
    var traveledDistance:Double = 0

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.locationManager.delegate = self
        self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
        self.locationManager.requestWhenInUseAuthorization()
        self.locationManager.startUpdatingLocation()
        self.mapView.showsUserLocation = true

        startLocation = nil
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    //MARK: Location Delegate Methods

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

        let location = locations.last

        let center1 = CLLocationCoordinate2D(latitude: location!.coordinate.latitude , longitude: location!.coordinate.longitude)

        let region1 = MKCoordinateRegion(center: center1, span: MKCoordinateSpan(latitudeDelta: 0.01, longitudeDelta: 0.01))

        self.mapView.setRegion(region1, animated: true)

        self.locationManager.stopUpdatingLocation()


        if startLocation == nil {
            startLocation = location
        }

        let distanceBetween: CLLocationDistance =
            location!.distance(from: startLocation)

        distance1.text = String(format: "%.2f", distanceBetween)
    }


    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        print("Error: " + error.localizedDescription)
    }

}

`distance1.text = String(format: "%.2f", distanceBetween)`, this line? What is the output of `print(distanceBetween)` ? And is Label's IBOutlet is connected? — Bista, Sep 29 '16 at 05:36
0.0 0.000203653973896072 0.0 0.0293734711867961 0.058756179207904 1.49467991968046 1.49467991968046 1.52405981650563 2016-09-29 00:39:02.646522 WaterCollection[618:80909] [App] if we're in the real pre-commit handler we can't actually add any new fences due to CA restriction this is the output i'm getting — Prudhvi Nallamanikaluva, Sep 29 '16 at 05:39
Distance should be some logical number, this is the whole output you get? — Bista, Sep 29 '16 at 05:41
I guess its the double number **0.0** **0.000203653973896072** **0.0293734711867961** those are the output i'm getting — Prudhvi Nallamanikaluva, Sep 29 '16 at 05:43
`distanceBetween` is giving two three outputs `0.0`, `0.000203653973896072` and `0.0293734711867961`? — Bista, Sep 29 '16 at 05:50
no I'm getting many values, since i'm keeping my phone connected to laptop and roaming around — Prudhvi Nallamanikaluva, Sep 29 '16 at 06:07
Have you liked the label in your storyboard with the `distance1` outlet? — Paulw11, Sep 29 '16 at 06:16
yes i have linked it, the basic problem is to printing the distancebetween values on distance1 — Prudhvi Nallamanikaluva, Sep 29 '16 at 06:41

fatal error: unexpectedly found nil while unwrapping an Optional value while printing on UILabel

0 Answers0