How do I make an enum Decodable in swift 4?

Question

enum PostType: Decodable {

    init(from decoder: Decoder) throws {

        // What do i put here?
    }

    case Image
    enum CodingKeys: String, CodingKey {
          


        

Answer 1

It's pretty easy, just use String or Int raw values which are implicitly assigned.

enum PostType: Int, Codable {
    case image, blob
}

image is encoded to 0 and blob to 1

Or

enum PostType: String, Codable {
    case image, blob
}

image is encoded to "image" and blob to "blob"

---

This is a simple example how to use it:

enum PostType : Int, Codable {
    case count = 4
}

struct Post : Codable {
    var type : PostType
}

let jsonString = "{\"type\": 4}"

let jsonData = Data(jsonString.utf8)

do {
    let decoded = try JSONDecoder().decode(Post.self, from: jsonData)
    print("decoded:", decoded.type)
} catch {
    print(error)
}