If you're starting from the JSON string value and are trying to get a JToken from it, use JToken.Parse
:
JToken token = JToken.Parse("[\"hyundai\",{}]");
Or, you can manually create a JToken that resolves to the JSON string ["hyundai",{}]
like this:
JArray token = new JArray();
token.Add(new JValue("hyundai"));
token.Add(new JObject());
To convert a JToken to JSON, just use ToString
:
string json = token.ToString(Formatting.None);