FTD Hyderabad | Dotnet interview | November 7 2016 | Experienced

Hi All,

I wanted to share interview questions asked at FTD Hyderabad Interview for Dot Net developer experienced candidate.

Please use the questions as reference and research the answers for self understanding
The questions are as follows

1. Introduce yourself

2. In which topics are you comfortable

C# OOPS :

1. Tell me about Hash table vs Dictionary

2.What are dey and which is faster

     Dictionary is faster as it is strongly typed

3.  What is the difference

4. Boxing and unboxing

5. Array and array list are having same number of elements or Size which is faster and why it is fast

 Array will be faster in this case when compared to ArrayList as the implementation of the arrayList in the internal side is an array. As ArrayList will allow different datatypes to save it requires boxing and unboxing which makes it slow.

 Along with that ArrayList

4.Using key usage why ?

5 Memory leakage

https://msdn.microsoft.com/en-us/library/ms998530.aspx

Run a profiler on your code.

Here are two good options:

RedGate's memory profiler

Jetbrains dotTrace

Memory leaks in .NET are not that common, but when they happen it is most commonly due to unattached event handlers. Make sure you detach handlers, before the listeners go out of scope.

Another option is if you forget to call Dispose() on IDisposable resources. This may prevent cleanup of unmanaged resources (which are not handled by GC).

6. Is Webservice method overloading possible ?  and How it can be achieved ?

The function overloading in Web Service is not as straightforward as in class. While trying to overload member function, we make two or more methods with the same name with different parameters. But this will not work in web services and will show runtime error because WSDL is not supported by the same method name

The procedure to solve this problem is very easy. Start each method with a Web Method attribute. Add Description property to add a description of web method and MessageName property to change web method name.

[WebMethod(MessageName = "<name>", Description = "<description>")]

Hide   Copy Code

namespace TestOverloadingWebService

{

    [WebService(Namespace = "http://tempuri.org/", Description=" <b> Function

    overloading in Web Services </b>")]

public class OverloadingInWebService : System.Web.Services.WebService

{

    [WebMethod(MessageName = "AddInt", Description = "Add two integer

        Value", EnableSession = true)]

    public int Add(int a, int b)

    {

        return (a + b);

    }

    [WebMethod(MessageName = "AddFloat", Description = "Add two Float 

        Value", EnableSession = true)]

    public float Add(float a, float b)

    {

        return (a + b);

    }

}

}

7. GAC What is global assembly cache

Global Assembly Cache

Each computer where the common language runtime is installed has a machine-wide code cache called the global assembly cache. The global assembly cache stores assemblies specifically designated to be shared by several applications on the computer.

Use a developer tool called the Global Assembly Cache tool (Gacutil.exe), provided by the Windows Software Development Kit (SDK).

Starting with the .NET Framework 4, the default location for the global assembly cache is %windir%\Microsoft.NET\assembly.

In earlier versions of the .NET Framework, the default location is %windir%\assembly.

8. What is presistent cookie

9. What are cookies

10. What is session management, how did you apply session management is your application

    

https://msdn.microsoft.com/en-us/library/z1hkazw7.aspx

Server side session

         4 types

            Application state session

Session state

Profile properties

Database support           

     Client side session

         View state

            Control state

        Hidden fields

        Cookies

       Query strings

11. How can session state is maintained in your application

12. What is client side session and server side

13. What is View bag and view data

       Which is dynamic

       viewBag.foo - dynamic

       viewData["foo"]

14. Similarities between ViewBag & ViewData , which is dynamic

Helps to maintain data when you move from controller to view. Used to pass data from controller to corresponding view. Short life means value becomes null when redirection occurs. This is because their goal is to provide a way to communicate between controllers and views. It’s a communication mechanism within the server call.

Difference between ViewBag & ViewData:

ViewData is a dictionary of objects that is derived from ViewDataDictionary class and accessible using strings as keys. ViewBag is a dynamic property that takes advantage of the new dynamic features in C# 4.0. ViewData requires typecasting for complex data type and check for null values to avoid error. ViewBag doesn’t require typecasting for complex data type

ViewData: It’s required type casting for complex data type and check for null values to avoid error.

ViewBag: It doesn’t require type casting for complex data type.

Consider the following example:

public class HomeController : Controller

{

    public ActionResult Index()

    {

        var emp = new Employee

        {

            EmpID=101,

            Name = "Deepak",

            Salary = 35000,

            Address = "Delhi"

        };

        ViewData["emp"] = emp;

        ViewBag.Employee = emp;

        return View();

    }

}

And the code for View is as follows:

@model MyProject.Models.EmpModel;

@{

 Layout = "~/Views/Shared/_Layout.cshtml";

 ViewBag.Title = "Welcome to Home Page";

 var viewDataEmployee = ViewData["emp"] as Employee; //need type casting

}

<h2>Welcome to Home Page</h2>

This Year Best Employee is!

<h4>@ViewBag.emp.Name</h4>

<h3>@viewDataEmployee.Name

-------------------------------------------------------------------------

18. Can we have catch without try and finally

19. Try and finally without Catch

try need either catch or finally for sure.

but not both catch and finally are mandatory.

20. What is deferred execution LINQ

LINQ query, you always work with objects. The object may in-process object or out-process object. Based on objects, LINQ query expression is translated and executed. There are two ways of LINQ query execution

 a . In case of differed execution,

a query is not executed at the point of its declaration. It is executed when the Query variable is iterated by using loop like as for, foreach.

DataContext context = new DataContext();

var query = from customer in context.Customers

 where customer.City == "Delhi"

 select customer; // Query does not execute here

 foreach (var Customer in query) // Query executes here

 {

 Console.WriteLine(Customer.Name);

 }

 A LINQ query expression often causes deferred execution. Deferred execution provides the facility of query reusability, since it always fetches the updated data from the data source which exists at the time of each execution.

b. Immediate Execution

In case of immediate execution, a query is executed at the point of its declaration. The query which returns a singleton value (a single value or a set of values) like Average, Sum, Count, List etc. caused Immediate Execution.

You can force a query to execute immediately of by calling ToList, ToArray methods.

DataContext context = new DataContext();

var query = (from customer in context.Customers

 where customer.City == "Delhi"

 select customer).Count(); // Query execute here

Immediate execution doesn't provide the facility of query re-usability since it always contains the same data which is fetched at the time of query declaration

22. What is routing .and Uses

  APP_sTART RouteConfig.  RegisterRoutes in RouteConfig cls.

route = {controller}/{action}/{id. optional}

WebApi.RouteConfig

  api/{controller}/{action}/{id}

23. Can we pass data from one controller to other controller

24. What are 'Action Filters'

Using an Action Filter

An action filter is an attribute. You can apply most action filters to either an individual controller action or an entire controller.

An action filter is an attribute that you can apply to a controller action -- or an entire controller -- that modifies the way in which the action is executed. The ASP.NET MVC framework includes several action filters:

OutputCache – This action filter caches the output of a controller action for a specified amount of time.

HandleError – This action filter handles errors raised when a controller action executes.

Authorize – This action filter enables you to restrict access to a particular user or role

For example, the Data controller in Listing 1 exposes an action named Index() that returns the current time. This action is decorated with the OutputCache action filter. This filter causes the value returned by the action to be cached for 10 seconds.

Listing 1 – Controllers\DataController.cs

using System;

using System.Web.Mvc;

namespace MvcApplication1.Controllers

{

     public class DataController : Controller

     {

          [OutputCache(Duration=10)]

          public string Index()

          {

               return DateTime.Now.ToString("T");

          }

     }

}