When using the new JSONDecoder protocol in Swift 4 i'm getting the 'the data couldn’t be read because it isn’t in the correct format.' error

Question

Kinda New to swift and haven't seen a solution for this error using swift 4.

When using the JSONDecoder function I've been getting an error saying that 'the data couldn't be read because it isn't in the correct format.' I've run my JSON through a validator and it's saying everything is ok there so I'm just not understanding why this error is happening

my code for decoding is as follows:

import UIKit

class inputscreen: UIViewController {
// the JSONData.php is where the data is being converted into JSON using PhP
    final let url = URL(string: "JSONData.php")

    override func viewDidLoad() {
        super.viewDidLoad()
        downloadJson()

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
func downloadJson() {
    guard let downloadURL = url else {return }
    URLSession.shared.dataTask(with: downloadURL) {data, urlResponse, error in

            guard let data = data, error == nil, urlResponse != nil else {
               print("something went wrong")
               return

            }
           // print(data)
            print("downloaded")
            do {
                // this is where the error is happening, everything else is getting through my checks.
                let decoder = JSONDecoder()
                let variables = try decoder.decode(Variables.self, from:data)
                print(variables.variables[0].TblStaffID)
                print("success")

            } catch {
               print(error.localizedDescription)

          }
        }.resume()
    }
}

in the JSON I've converted it to UTF8 so I don't think that's where the error is coming from

I have the struct for this in a different file which looks like this:

    import Foundation
    import UIKit

class Variables: Codable{

let variables: [Variable]
init(variables: [Variable]){
    self.variables = variables
}

}

struct Variable: Codable {
    let TblStaffID: Int
    let User_code: String
    let Title: String
    let PreName: String
    let Surname: String
  init(TblStaffID: Int, User_code: String, Title: String, PreName: String, Surname: String){

        self.TblStaffID = TblStaffID
        self.User_code = User_code
        self.Title =  Title
        self.PreName = PreName
        self.Surname = Surname
    }
}

any and all help on this matter would be appreciated!

Answer 1

确保将日期格式转换为TimeIntervals或String