Return JSON Data from ASP.NET MVC Controllers

Send JSON Content welcome note based on user type

using System;  
using System.Collections.Generic;  
using System.Text;  
using System.Web.Mvc;  
using System.Web.Script.Serialization;  
using JsonResultDemo.Models;  
namespace JsonResultDemo.Controllers  
    public class JsonDemoController : Controller  
        #region ActionControllers  
        /// <summary>  
        /// Welcome Note Message  
        /// </summary>  
        /// <returns>In a Json Format</returns>  
        public JsonResult WelcomeNote()  
            bool isAdmin = false;  
            //TODO: Check the user if it is admin or normal user, (true-Admin, false- Normal user)  
            string output = isAdmin ? "Welcome to the Admin User" : "Welcome to the User";  
            return Json(output, JsonRequestBehavior.AllowGet);  

Get the list of users in JSON Format

/// <summary>  
/// Update the user details  
/// </summary>  
/// <param name="usersJson">users list in JSON Format</param>  
/// <returns></returns>  
public JsonResult UpdateUsersDetail(string usersJson)  
    var js = new JavaScriptSerializer();  
    UserModel[] user = js.Deserialize<UserModel[]>(usersJson);  
    //TODO: user now contains the details, you can do required operations  
    return Json("User Details are updated");