using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/58924421/add-jobject-to-another-jobject-in-net

​

    class TestClass

    {

        public static void Test()

        {

            var jObject1 = JObject.Parse(GetJson1());

            var jObject2 = JObject.Parse(GetJson2());

            ((JObject)jObject1["data"]["organism"]["human"][0]).Add(jObject2.Property("degrees"));

            Console.WriteLine(jObject1);

            Assert.IsTrue(JToken.DeepEquals(jObject1, JToken.Parse(GetRequiredJson())));

        }   

        static string GetRequiredJson()

        {

            var json = @"{

  ""data"": {

    ""organism"": {

      ""human"": [

        {

          ""firstName"": ""John"",

          ""lastName"": ""Doe"",

          ""degrees"": [

            {

              ""type"": ""bachelor"",

              ""major"": ""Math""

            },

            {

              ""type"": ""master"",

              ""major"": ""Computer Science""

            }

          ]

        }

      ]

    }

  }

}";

            return json;

        }

        static string GetJson1()

        {

            var json = @"{

  ""data"": {

    ""organism"": {

      ""human"": [

        {

          ""firstName"": ""John"",

          ""lastName"": ""Doe""

        }

      ]

    }

  }

}

";

            return json;

        }

        static string GetJson2()

        {

            var json = @"{

  ""degrees"": [

    {

      ""type"": ""bachelor"",

      ""major"": ""Math""

    },

    {

      ""type"": ""master"",

      ""major"": ""Computer Science""

    }

  ]

}

";

            return json;

        }

    }

​

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.CodeBase.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​