У меня есть класс с именемLocation в нем есть несколько методов, которые не имеют никаких параметров.

Однако, когда я пытаюсь создать переменную с результатом метода, он хочет аргумент. Это почему?

Location учебный класс:

let locationManager = CLLocationManager()

public class Location {

    public func coordinate() -> (latitude: Float?, longitude: Float?) {
        let latitude = Float((locationManager.location?.coordinate.latitude)!)
        let longitude = Float((locationManager.location?.coordinate.longitude)!)

        return (latitude: latitude, longitude: longitude)
    }

    public func getCity() -> String {
        var returnCity: String = "N/A"
        let geoCoder = CLGeocoder()
        let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)

        geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
            // Place details
            var placeMark: CLPlacemark!
            placeMark = placemarks?[0]
            // City
            if let city = placeMark.addressDictionary!["City"] as? String {
                returnCity = city
            }
        })
        return returnCity
    }

    public func getCountry() -> String {
        var returnCountry: String = "N/A"
        let geoCoder = CLGeocoder()
        let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)

        geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
            // Place details
            var placeMark: CLPlacemark!
            placeMark = placemarks?[0]
            // City
            if let country = placeMark.addressDictionary!["Country"] as? String {
                returnCountry = country
            }
        })
        return returnCountry
    }

    public func getZip() -> Int {
        var returnZip: Int = 0
        let geoCoder = CLGeocoder()
        let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)

        geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
            // Place details
            var placeMark: CLPlacemark!
            placeMark = placemarks?[0]
            // City
            if let zip = placeMark.addressDictionary!["ZIP"] as? Int {
                returnZip = zip
            }
        })
        return returnZip
    }

    public func getLocationName() -> String {
        var returnName: String = "N/A"
        let geoCoder = CLGeocoder()
        let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)

        geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
            // Place details
            var placeMark: CLPlacemark!
            placeMark = placemarks?[0]
            // City
            if let locationName = placeMark.addressDictionary!["Name"] as? String {
                returnName = locationName
            }
        })
        return returnName
    }

    public func getStreetAddress() -> String {
        var returnAddress: String = "N/A"
        let geoCoder = CLGeocoder()
        let location = CLLocation(latitude: (locationManager.location?.coordinate.latitude)!, longitude: (locationManager.location?.coordinate.longitude)!)

        geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
            // Place details
            var placeMark: CLPlacemark!
            placeMark = placemarks?[0]
            // City
            if let street = placeMark.addressDictionary!["Thoroughfare"] as? String {
                returnAddress = street
            }
        })
        return returnAddress
    }
}

Попытка создать переменную:

let city = Location.getCity()

Вот несколько скриншотов того, что я получаю: