JSON - Jagged Array Deserialization

Question

I do have a question, it maybe a beginner's question but am not really very familiar with JSON. however, am trying to de-serialize the below JSON using C# Newtonsoft.Json, however, it keeps failing, can anyone please advise how to de-serialize it & how it has to be modeled in C#?

[
    {
        "fields": [
            [
                "name",
                "value",
                "values",
                "error"
            ],
            [
                "correspondsApi",
                "N",
                null,
                ""
            ],
            [
                "username",
                "test@test.com",
                null,
                ""
            ],
            [
                "password",
                "",
                null,
                ""
            ],
            [
                "accountid",
                "",
                null,
                ""
            ],
            [
                "rememberMe",
                "Y",
                null,
                ""
            ],
            [
                "language",
                "en-US",
                null,
                ""
            ],
            [
                "S",
                "tokenValue",
                null,
                null
            ],
            [
                "authToken",
                "",
                null,
                ""
            ]
        ],
        "success": "Y",
        "message": "Access is granted"
    }
]

Below is the code that I have tried which keeps throwing an exception: MODEL:

public class MyArray
    {
        public List<List<string>> fields { get; set; }
        public string success { get; set; }
        public string message { get; set; }
    }

    public class Root
    {
        public List<MyArray> MyArray { get; set; }
    }

CODE:

using Newtonsoft.Json;

static void Main(string[] args)
{     
   string jsonContent = "[{\"fields\":[[\"name\",\"value\",\"values\",\"error\"],[\"correspondsApi\",\"N\",null,\"\"],[\"username\",\"test@test.com\",null,\"\"],[\"password\",\"\",null,\"\"],[\"accountid\",\"\",null,\"\"],[\"rememberMe\",\"Y\",null,\"\"],[\"language\",\"en-US\",null,\"\"],[\"S\",\"tokenValue\",null,null],[\"authToken\",\"\",null,\"\"]], \"success\":\"Y\",\"message\":\"Access is granted\"}]";
            JsonConvert.DeserializeObject<Root>(jsonContent);
            
}

EXCEPTION:

Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'LearningOnly.Root' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly. To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array. Path '', line 1, position 1.'

Does this answer your question? [How to auto-generate a C# class file from a JSON string](https://stackoverflow.com/questions/21611674/how-to-auto-generate-a-c-sharp-class-file-from-a-json-string) — Liam, Oct 05 '20 at 09:05
@Liam unfortunately no, I have already modified the question and added more details. — Yazantamimi Al-Tamimi, Oct 05 '20 at 09:58
Hello @less, I already have added more details, I have tried different modeling but in the end I keep facing an error. — Yazantamimi Al-Tamimi, Oct 05 '20 at 09:59

score 0 · Accepted Answer · answered Oct 05 '20 at 10:34

Your json and objects don't match. To use Root you would need json like {MyArray: [...]}, i.e. an object with a MyArray property containing an array. But you don't. You actually want to use:

JsonConvert.DeserializeObject<List<MyArray>>(jsonContent);

Because your root json structure is an array, i.e. [{},{}] not an object. so you need to turn it into an enumerator (List<> or array, etc.)

Working example here: https://dotnetfiddle.net/zA4VLA

score -2 · Answer 2 · answered Oct 05 '20 at 09:10

-2

I ran your json in https://json2csharp.com/

Answer to your question: "how it has to be modeled in C#?"

public class MyArray    {
    public List<List<string>> fields { get; set; } 
    public string success { get; set; } 
    public string message { get; set; } 
}

public class Root    {
    public List<MyArray> MyArray { get; set; } 
}

answered Oct 05 '20 at 09:10

syp_dino

395
3
10

Hello Syp_dino. I actually tried that solution, but it is not working out, it is giving me this error: Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'LearningOnly.Root' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly. To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface – Yazantamimi Al-Tamimi Oct 05 '20 at 09:50

JSON - Jagged Array Deserialization

2 Answers2