How to add json property and value to an empty collection in a jobject?

Question

I have a Jobject Car .
The Car has a null collection 'wheels'.

How could I add property and values to the collection wheels ?

Code:

{
  "Car": {
    "engine": 2,
    "wheels": []
  }
}

What I expect:

{
  "Car": {
    "engine": 2,
    "wheels": [
      {
        "frontWheel": 2,
        "rearWheel": 2
      }
    ]
  }
}

How to add frontwheel and rearwheel to the JObject ?

Answer 1

To create your desired output using Newtonsoft.Json , you create an instance of JArray and populate it with instances of type JObject .

var result = new JObject(
    new JProperty("engine", 2),
    new JProperty("wheels", 
        new JArray
        {
            new JObject(
                new JProperty("frontWheel", 2),
                new JProperty("rearWheel", 2))
        }));

This will produce the following output:

{
  "engine": 2,
  "wheels": [
    {
      "frontWheel": 2,
      "rearWheel": 2
    }
  ]
}

Alternatively you could use the serialization mechanism provided by Newtonsoft.Json