将 json 转换为 Apple Swift 中的字符串数组数组

Question

I am writing my first Swift program (Swift 5.1) using Xcode.

I am struggling. All I want to do is convert a json string into two arrays of arrays. A good tutorial is here https://developer.apple.com/swift/blog/?id=37 but it is just too complex.

An example json string is below.

{
  "Animals" :
  {
   "Mice" : ["Mickey", "Minnie"],
   "Ducks" : ["Donald", "Daisy"],
   "Elephants" : ["Dumbo", "Yzma"]
  },
  "Movies" :
  {
   "1940s" : ["Pinocchio", "Fantasia", "Dumbo"],
   "1950s" : ["Cinderella", "Treasure Island", "Peter Pan"],
   "1960s" : ["The Signs of Zorro", "Swiss Family Robinson", "Mary Poppins"],
   "1970s" : ["Herbie Rides Again", "Herbie Goes to Monte Carlo", "Freaky Friday"] 
  }
}

All I want is minimal crappy code that I can paste into a Swift playground to creates two arrays of arrays so in arrayAnimal[0][1] is Minnie, arrayAnimal[2][0] is Dumbo, and arrayMovie[3][1] is Herbie Goes to Monte Carlo for example.

If it is possible use arrayAnimal["mice"][1] to get Minnie this is perfect, but for now my focus is working out how I should deserialize the json in Swift to get the arrays of arrays.

Thank you

Answer 1

Firstly you need this codable model for your json. you should add it in separate swift file:

  struct MyModel: Codable {
    let animals: Animals
    let movies: [String: [String]]

    enum CodingKeys: String, CodingKey {
        case Animals
        case Movies
    }
}

// MARK: - Animals
struct Animals: Codable {
    let mice, ducks, elephants: [String]

    enum CodingKeys: String, CodingKey {
        case Mice
        case Ducks
        case Elephants
    }

}

then you need to convert your string to Data :

let jsonData: Data? = jsonString.data(using: .utf8)

then you can easily decode your data to desired object.

let decoder = JSONDecoder()

do {
    let myModel= try decoder.decode(MyModel.self, from: jsonData)
} catch {
    print(error.localizedDescription)
}

in the end you can access your desired data through your decoded object. for example :

let anArrayOfStringsOfMices = myModel.animals.mice