How do I parse a JSON object in C# when I don't know the key in advance?

Question

I have some JSON data that looks like this:

{
  "910719": {
    "id": 910719,
    "type": "asdf",
    "ref_id": 7568
  },
  "910721": {
    "id": 910721,
    "type": "asdf",
    "ref_id": 7568
  },
  "910723": {
    "id": 910723,
    "type": "asdf",
    "ref_id": 7568
  }
}

How can I parse this using JSON.net? I can first do this:

JObject jFoo = JObject.Parse(data);

I need to be able to iterate over each object in this list. I would like to be able to do something like this:

foreach (string ref_id in (string)jFoo["ref_id"]) {...}

or

foreach (JToken t in jFoo.Descendants())
{
    Console.WriteLine((string)t["ref_id"]);
}

but of course that doesn't work. All the examples work great if you know the key while writing your code. It breaks down when you don't know the key in advance.

Answer 1

It's doable; this works but it's not elegant. I'm sure there's a better way.

var o = JObject.Parse(yourJsonString);

foreach (JToken child in o.Children())
{
    foreach (JToken grandChild in child)
    {
        foreach (JToken grandGrandChild in grandChild)
        {
            var property = grandGrandChild as JProperty;

            if (property != null)
            {
                Console.WriteLine(property.Name + ":" + property.Value);
            }
        }
    }
}

Prints:

id:910719
type:asdf
ref_id:7568
id:910721
type:asdf
ref_id:7568
id:910723
type:asdf
ref_id:7568

Answer 2

You can iterate over the child objects with a simple LINQ query like this:

JObject jFoo = JObject.Parse(json);

foreach (JObject obj in jFoo.Properties().Select(p => p.Value))
{
    Console.WriteLine("id: " + obj["id"]);
    Console.WriteLine("type: " + obj["type"]);
    Console.WriteLine("ref_id: " + obj["ref_id"]);
}

Fiddle: https://dotnetfiddle.net/fwINPa

Or if you just want all the ref_id values, you can do something like this:

string[] refIds = jFoo.Properties()
                      .Select(p => (string)p.Value["ref_id"])
                      .ToArray();

Console.Write(string.Join("\r\n", refIds));

Fiddle: https://dotnetfiddle.net/twOuVY