c# object to json string

using Newtonsoft.Json;

var jsonString = JsonConvert.SerializeObject(obj);

Newtonsoft.Json.JsonConvert.SerializeObject(new {foo = "bar"})

var person={"first_name":"Tony","last_name":"Hawk","age":31};
var personJSONString=JSON.stringify(person); 

var json = new JavaScriptSerializer().Serialize(obj);

using System;
using System.Web.Script.Serialization;

public class MyDate
{
    public int year;
    public int month;
    public int day;
}

public class Lad
{
    public string firstName;
    public string lastName;
    public MyDate dateOfBirth;
}

class Program
{
    static void Main()
    {
        var obj = new Lad
        {
            firstName = "Markoff",
            lastName = "Chaney",
            dateOfBirth = new MyDate
            {
                year = 1901,
                month = 4,
                day = 30
            }
        };
        var json = new JavaScriptSerializer().Serialize(obj);
        Console.WriteLine(json);
    }
}

JObject json = JObject.Parse(str);