using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Diagnostics;

using System.IO;

using System.Threading;

using System.Collections;

using System.Runtime.Serialization;

using System.Dynamic;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;

​

​

    public static class JsonExtensions

    {

        public static JToken ReplacePath<T>(this JToken root, string path, T newValue)

        {

            if (root == null || path == null)

                throw new ArgumentNullException();

​

            foreach (var value in root.SelectTokens(path).ToList())

            {

                if (value == root)

                    root = JToken.FromObject(newValue);

                else

                    value.Replace(JToken.FromObject(newValue));

            }

​

            return root;

        }    

​

        public static string ReplacePath<T>(string jsonString, string path, T newValue)

        {

            return JToken.Parse(jsonString).ReplacePath(path, newValue).ToString();

        }    

    }

​

    public class TestClass

    {

        static string GetJson()

        {

            var json = @"{ ""store"": {

    ""book"": [ 

      { ""category"": ""reference"",

        ""author"": ""Nigel Rees"",

        ""title"": ""Sayings of the Century"",

        ""price"": 8.95

      },

      { ""category"": ""fiction"",

        ""author"": ""Evelyn Waugh"",

        ""title"": ""Sword of Honour"",

        ""price"": 12.99

      },

      { ""category"": ""fiction"",

        ""author"": ""Herman Melville"",

        ""title"": ""Moby Dick"",

        ""isbn"": ""0-553-21311-3"",

        ""price"": 8.99

      },

      { ""category"": ""fiction"",

        ""author"": ""J. R. R. Tolkien"",

        ""title"": ""The Lord of the Rings"",

        ""isbn"": ""0-395-19395-8"",

        ""price"": 22.99

      }

    ],

    ""bicycle"": {

      ""color"": ""red"",

      ""price"": 19.95

    }

  }

}";

            return json;

        }

​

        public static void Test()

        {

            var jsonString = GetJson();

​

            ConsoleAndDebug.WriteLine("\nInitial JSON:\n");

            ConsoleAndDebug.WriteLine(JToken.Parse(jsonString));

​

            var newJsonAuthorString = JsonExtensions.ReplacePath(jsonString, @"$.store.book[*].author", "NewAuthorSpecifiedByUser");

​

            ConsoleAndDebug.WriteLine("\nModified JSON author properties:\n");

            ConsoleAndDebug.WriteLine(newJsonAuthorString);

            var newJsonArrayString = JsonExtensions.ReplacePath(jsonString, @"$.store.book[*]", "NewAuthorSpecifiedByUser");

​

            ConsoleAndDebug.WriteLine("\nModified JSON array elements:\n");

            ConsoleAndDebug.WriteLine(newJsonArrayString);

            var newJsonRootString = JsonExtensions.ReplacePath(jsonString, @"", new { author = "NewAuthorSpecifiedByUser" });

            ConsoleAndDebug.WriteLine("\nModified JSON root element:\n");

            ConsoleAndDebug.WriteLine(newJsonRootString);

        }

    }

    public static class ConsoleAndDebug

    {

        public static void WriteLine(object s)

        {

            Console.WriteLine(s);

            Debug.WriteLine(s);

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine(string.Format("Json.NET version: {0}.\n", typeof(JsonSerializer).Assembly.FullName));         

            TestClass.Test();

        }

    }

​