How to parse Array of JSON to array in Swift

Question

I\'m trying to parse JSON which is like below

[
  {
    "People": [
      "Jack",
      "Jones",
      "Rock",
      &         


        

Answer 1

You can do this in an elegant and type safe way leveraging Swift 4 Decodable

First define a type for your people array.

struct People {
  let names: [String]
}

Then make it Decodable, so that it can be initialised with a JSON.

extension People: Decodable {

  private enum Key: String, CodingKey {
    case names = "People"
  }

  init(from decoder: Decoder) throws {
    let container = try decoder.container(keyedBy: Key.self)

    self.names = try container.decode([String].self, forKey: .names)
  }
}

Now you can easily decode your JSON input

guard
  let url = Bundle.main.url(forResource: "People", withExtension: "json"),
  let data = try? Data(contentsOf: url)
else { /* Insert error handling here */ }

do {
  let people = try JSONDecoder().decode([People].self, from: data)
} catch {
  // I find it handy to keep track of why the decoding has failed. E.g.:
  print(error)
  // Insert error handling here
}

Finally to get get your linear array of names you can do

let names = people.flatMap { $0.names }
// => ["Jack", "Jones", "Rock", "Taylor", "Rob", "Rose", "John", "Ted"]