how can ı do Value of type double if null

Question

    @IBAction func addLocation(_ sender: UIButton) {
        //eklenen konumu ve verilerini kaydetme
        if nameText.text == ""{
            makeAlert(tıtleInput: "Error", messageInput: "İsim boş geçilemez!")
        }
        else if commentText.text == ""{
            makeAlert(tıtleInput: "Error", messageInput: "Yorum boş geçilemez!")
        }
        else if choosenLatitude == nil  && choosenLongitude == nil {
            makeAlert(tıtleInput: "Error", messageInput: "Lütfen konumunuzu seçin")
        }
        else{
            let appDelegate = UIApplication.shared.delegate as! AppDelegate
            let context = appDelegate.persistentContainer.viewContext
            
            let newPlace = NSEntityDescription.insertNewObject(forEntityName: "Places", into: context)
            
            newPlace.setValue(nameText.text, forKey:"title")
            newPlace.setValue(commentText.text, forKey: "subtitle")
            newPlace.setValue(self.choosenLongitude, forKey: "longitude")
            newPlace.setValue(self.choosenLatitude, forKey: "latitude")
            newPlace.setValue(UUID(), forKey: "id")

I want it to throw an error if chosenlatitude and chosenlongitude are empty, but I don't know how to do this in the double variable.

the error i got Comparing non-optional value of type 'Double' to 'nil' always returns false