拆解-可选值[重复]时意外发现nil

可选值

struct StoreProducts: Decodable {
  let totalProducts: Int?
  let pageNumber: Int?
}

var products: StoreProducts!

override func viewDidLoad() {
    super.viewDidLoad()

    fetchProducts(completion: { success in
        print(self.products as Any)
        self.products = products
        self.productTableView.reloadData()
    })
}

func fetchProducts(completion: @escaping ((Any) -> Void)) {
    let jsonUrlString = "https://mobile-server.com/products/1/20"
    guard let url = URL(string: jsonUrlString) else { return  }

    // Note: Swift 4 JSONCoder()
    URLSession.shared.dataTask(with: url) { (data, response, err) in
        guard let data = data else { return }
        do {
            // getting error here
            self.products = try JSONDecoder().decode(StoreProducts.self, from: data)
            //check response status 200 OK
            if pageProducts.statusCode != 200
            {
                print("Connection issue, please try again later")
            }
            else{
                completion(self.products as Any)
            }
        }
        //check error
        catch let jsonErr {
            print("Error serializing json:", jsonErr)
        }
    }.resume()
}