Codable: Expected to decode Array<Any> but found a dictionary instead

Question

I'm new to Codable and been playing around it today.

My current JSON model look like this:

{
    "status": 200,
    "code": 200,
    "message": {
        "1dHZga0QV5ctO6yhHUhy": {
            "id": "23",
            "university_location": "Washington_DC",
            "docID": "1dHZga0QV5ctO6yhHUhy"
        },
        "0dbCMP7TrTEnpRbEleps": {
            "id": "22",
            "university_location": "Timber Trails, Nevada",
            "docID": "0dbCMP7TrTEnpRbEleps"
        }
    }
}

However, Trying to decode this response with:

    struct USA: Codable
{
    //String, URL, Bool and Date conform to Codable.
    var status: Int
    var code: Int

    // Message Data
    var message: Array<String>

}

Gives out:

Expected to decode Array but found a dictionary instead.

Updating the message to Dictionary<String,String produces:

typeMismatch(Swift.String, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "message", intValue: nil), _JSONKey(stringValue: "1dHZga0QV5ctO6yhHUhy", intValue: nil)], debugDescription: "Expected to decode String but found a dictionary instead.", underlyingError: nil))

I recommend pasting your JSON into app.quicktype.io to get a very reasonable first version of the struct(s) you'll need in Swift. — Gereon

Sh_Khan Sh_Khan · Accepted Answer · 2019-04-22T14:43:30

message key is a dictionary not an array

struct Root: Codable {
    let status, code: Int
    let message: [String: Message]
} 
struct Message: Codable {
    let id, universityLocation, docID: String

}

do { 
    let dec = JSONDecoder()
    dec.keyDecodingStrategy = .convertFromSnakeCase
    let res = try dec.decode(Root.self, from: data) 
}
catch{
    print(error)
}

Codable: Expected to decode Array<Any> but found a dictionary instead

1 Answers