I already know how to set up map pins or annotations like discussed here: https://developer.apple.com/forums/thread/651668 But the real question is: How do I replace the hardcoded location data with passed parameters? This Code is executed without problems, due to the fact that the coords in locations are hardcoded: import MapKit struct Location: Identifiable {     let id = UUID()     let name: String     let latitude: Double     let longitude: Double     var coordinate: CLLocationCoordinate2D {         CLLocationCoordinate2D(latitude: latitude, longitude: longitude)     } } struct MapView: View {     let locations = [Location(name: "Turtle Rock", latitude: 34.011_286, longitude: -116.166_868)]     var coordinate: CLLocationCoordinate2D     var lat: Double     var long: Double     @State private var region = MKCoordinateRegion()     var body: some View {         Map(coordinateRegion: $region,showsUserLocation: true, annotationItems: locations){ loco in             MapPin(coordinate: loco.coordinate)         }         .onAppear{             setRegion(coordinate)         }   .edgesIgnoringSafeArea(.all)     }     private func setRegion(_ coordinate: CLLocationCoordinate2D){         region = MKCoordinateRegion(             center: coordinate,             span: MKCoordinateSpan(latitudeDelta: 0.2, longitudeDelta: 0.2)         )     } } struct MapView_Previews: PreviewProvider {     static var previews: some View {         MapView(coordinate: CLLocationCoordinate2D(latitude: 34.011_286, longitude: -116.166_868),lat: 34.011_286, long: -116.166_868)     } } But as soon as I try to use lat(itude) or long(itude) or even coordinate from the passed parameters, I have to use lazy vars and therefore cannot access that mutable getters... any advice? let locations = [Location(name: "Turtle Rock", latitude: lat, longitude: long)] //this Throws: Cannot use instance member 'lat' within property initializer; property initializers run before 'self' is available. //Using lazy var results in: Cannot use mutating getter on immutable value: 'self' is immutable