1. N-Tier :

N-tier architecture is also called multi-tier architecture because the software is engineered to have th e processing, data management, and presentation functions physically and logically separated. That means that these different functions are hosted on several machines

2. What is MVC (Model view controller)?

Model–view–controller (MVC) is a software architectural pattern for implementing user interfaces. It divides a given software application into three interconnected parts, so as to separate internal representation of information from the way that information is presented to or accepted from the user.

MVC is a framework for building web applications using a MVC (Model View Controller) design:

The Model represents the application core (for instance a list of database records).
The View displays the data (the database records).
The Controller handles the input (to the database records).

3. List out different return types of a controller action method?

The base type of all these result types is ActionResult.

ViewResult (View): This return type is used to return a webpage from an action method.
PartialviewResult (Partialview): This return type is used to send a part of a view which will be rendered in another view.
RedirectResult (Redirect): This return type is used to redirect to any other controller and action method depending on the URL.
RedirectToRouteResult (RedirectToAction, RedirectToRoute): This return type is used when we want to redirect to any other action method.
ContentResult (Content): This return type is used to return HTTP content type like text/plain as the result of the action.
jsonResult (json): This return type is used when we want to return a JSON message.
javascriptResult (javascript): This return type is used to return JavaScript code that will run in browser.
FileResult (File): This return type is used to send binary output in response.
EmptyResult: This return type is used to return nothing (void) in the result.

4. What is the difference between Temp data, View, and View Bag?

ViewData

ViewData is used to pass data from controller to view.
It is derived from ViewDataDictionary class.
It is available for the current request only.
Requires typecasting for complex data type and checks for null values to avoid error.
If redirection occurs, then its value becomes null.

ViewBag

ViewBag is also used to pass data from the controller to the respective view.
ViewBag is a dynamic property that takes advantage of the new dynamic features in C# 4.0
It is also available for the current request only.
If redirection occurs, then its value becomes null.
Doesn’t require typecasting for complex data type.

TempData

TempData is derived from TempDataDictionary class
TempData is used to pass data from the current request to the next request
It keeps the information for the time of an HTTP Request. This means only from one page to another. It helps to maintain the data when we move from one controller to another controller or from one action to another action
It requires typecasting for complex data type and checks for null values to avoid error. Generally, it is used to store only one time messages like the error messages and validation messages

5. Explain what is the difference between View and Partial View?

A partial view is a chunk of HTML. Partial views can also be returned directly from controller methods.

View:

It contains the layout page.
Before any view is rendered, viewstart page is rendered.
View might have markup tags like body, html, head, title, meta etc.
View is not lightweight as compare to Partial View.

Partial View:

It does not contain the layout page.
Partial view does not verify for a viewstart.cshtml. We cannot put common code for a partial view within the viewStart.cshtml page.
Partial view is designed specially to render within the view and just because of that it does not consist any mark up.
We can pass a regular view to the RenderPartial method.

6. Explain the concept of MVC Scaffolding?

ASP.NET Scaffolding is a code generation framework for ASP.NET Web applications. Visual Studio 2013 includes pre-installed code generators for MVC and Web API projects.

7. What is Bundling and Minification in MVC?

Bundling and minification are two new techniques introduced to improve request load time. It improves load time by reducing the number of requests to the server and reducing the size of requested assets (such as CSS and JavaScript).

Bundling: It lets us combine multiple JavaScript (.js) files or multiple cascading style sheet (.css) files so that they can be downloaded as a unit, rather than making individual HTTP requests.

Minification: It squeezes out whitespace and performs other types of compression to make the downloaded files as small as possible. At runtime, the process identifies the user agent, for example IE, Mozilla, etc. and then removes whatever is specific to Mozilla when the request comes from IE.

8. What is meant by routing in MVC?

Routing is a mechanism in MVC that decides which action method of a controller class to execute. Without routing there's no way an action method can be mapped. To a request. Routing is a part of the MVC architecture so ASP.NET MVC supports routing by default.

9. What is linq in mvc ?

Language-Integrated Query (LINQ) is a powerful query language introduced with .Net 3.5 & Visual Studio 2008. LINQ can be used with C# or Visual Basic to query different data sources.

10. How to call view from another view in mvc4?

I have a view called LoggedIn.cshtml getting called from LoggedInController. Inside the LoggedInView I have a PartialView called _LoggedInPartial to display the nav bar containing different menus like Home, Profile, etc.

11. Service Oriented Architecture

A service-oriented architecture can be defined as a group of services, which communicate with each other. The process of communication involves either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.

Benefits

It is mainly for scalability and better performance.
An application wants to use some of the services provided by for other enterprises.

12. Object-Oriented Architecture c#

C# provides full support for object-oriented programming including encapsulation, inheritance, and polymorphism.

Encapsulation means that a group of related properties, methods, and other members are treated as a single unit or object.

Inheritance describes the ability to create new classes based on an existing class.

Polymorphism means that you can have multiple classes that can be used interchangeably, even though each class implements the same properties or methods in different ways.

13. ViewState

ViewState allows ASP.NET to repopulate form fields on each postback to the server, making sure that a form is not automatically cleared when the user hits the submit button.

14. Difference between stored procedure and function

a. Function must return a value but in Stored Procedure it is optional( Procedure can return zero or n values).

b. Functions can have only input parameters for it whereas Procedures can have input/output parameters .

c. Functions can be called from Procedure whereas Procedures cannot be called from Function.

15. What is ViewStart?

Razor View Engine introduced a new layout named _ViewStart which is applied on all view automatically. Razor View Engine firstly executes the _ViewStart and then start rendering the other view and merges them.

16. Explain in which assembly is the MVC framework is defined?

The MVC framework is defined in System.Web.Mvc.

17. Service-Oriented Architecture (SOA) Definition ?

A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed.

Service-oriented architectures are not a new thing. The first service-oriented architecture for many people in the past was with the use DCOM or Object Request Brokers (ORBs) based on the CORBA specification. For more on DCOM and CORBA, see Prior Service-Oriented Architectures.

Service-oriented architecture (SOA) is an evolution of distributed computing based on the request/reply design paradigm for synchronous and asynchronous applications. An application's business logic or individual functions are modularized and presented as services for consumer/client applications.

18. Object-Oriented Architecture ?

Object Oriented Architecture is an important concept for developing the software. It is a design paradigm based on the division of responsibilities for an application or system into individual reusable and self-sufficient objects. The popular approach of object-oriented design is to view a software system as a collection of entities known as objects. Object oriented is based on modeling real-world objects.

Advantages of Object-Oriented Architecture

· Object-Oriented architecture maps the application to real world objects for making it more understandable.

· It is easy to maintain and improves the quality of the system due to program reuse.

· This architecture provides reusability through polymorphism and abstraction.

· It has ability to manage the errors during execution. (Robustness)

· It has ability to extend new functionality and does not affected on the system.

· It improves testability through encapsulation.

· Object-Oriented architecture reduces the development time and cost.

Disadvantages of Object-Oriented Architecture

· Object-Oriented architecture has difficulty to determine all the necessary classes and objects required for a system.

· It is difficult to complete a solution within estimated time and budget because object-oriented architecture offers new kind of project management.

· This methodology do not lead to successful reuse on a large scale without an explicit reuse procedure.

Object Oriented Concepts

Object-Oriented architecture views a system as a series of cooperating objects, instead of a set of routines or procedural instructions. It is a significant methodology for the development of any software.

19. Polymorphism?

https://www.c-sharpcorner.com/UploadFile/ff2f08/understanding-polymorphism-in-C-Sharp/

Introduction

Polymorphism is a Greek word meaning "one name many forms". In other words, one object has many forms or has one name with multiple functionalities. "Poly" means many and "morph" means forms. Polymorphism provides the ability to class multiple implementations with the same name. It is one principle concept in Object Oriented Programming after encapsulation and inheritance.

Types of Polymorphism

There are basically the following two types of polymorphism in C#:

Static / Compile Time Polymorphism.
Dynamic / Runtime Polymorphism.

Static or Compile Time Polymorphism

It is also known as Early Binding. Method overloading is an example of Static Polymorphism. In Overloading, the method / function has the same name but different signatures. It is also known as Compile Time Polymorphism because the decision of which method is to be called is made at compile time. Overloading is the concept in which method names are the same with a different set of parameters.

Here the compiler checks the number of parameters passed and the type of parameter and make the decision of which method to call and it throw an error if no matching method is found.

In the following example the class has two methods with the same name "Add" but with different input parameters (the first method has three parameters and the second method has two parameters).

1. public class TestData

2. {

3. public int Add(int a, int b, int c)

4. {

5. return a + b + c;

6. }

7. public int Add(int a, int b)

8. {

9. return a + b;

10. }

11. }

12. class Program

13. {

14. static void Main(string[] args)

15. {

16. TestData dataClass = new TestData();

17. int add2 = dataClass.Add(45, 34, 67);

18. int add1 = dataClass.Add(23, 34);

19. }

20. }

Dynamic / Runtime Polymorphism

Dynamic / runtime polymorphism is also known as late binding. Here, the method name and the method signature (number of parameters and parameter type must be the same and may have a different implementation). Method overriding is an example of dynamic polymorphism.

Method overriding can be done using inheritance. With method overriding it is possible for the base class and derived class to have the same method name and same something. The compiler would not be aware of the method available for overriding the functionality, so the compiler does not throw an error at compile time. The compiler will decide which method to call at runtime and if no method is found then it throws an error.

1. public class Drawing

2. {

3. public virtual double Area()

4. {

5. return 0;

6. }

7. }

9. public class Circle : Drawing

10. {

11. public double Radius { get; set; }

12. public Circle()

13. {

14. Radius = 5;

15. }

16. public override double Area()

17. {

18. return (3.14) * Math.Pow(Radius, 2);

19. }

20. }

21.

22. public class Square : Drawing

23. {

24. public double Length { get; set; }

25. public Square()

26. {

27. Length = 6;

28. }

29. public override double Area()

30. {

31. return Math.Pow(Length, 2);

32. }

33. }

34.

35. public class Rectangle : Drawing

36. {

37. public double Height { get; set; }

38. public double Width { get; set; }

39. public Rectangle()

40. {

41. Height = 5.3;

42. Width = 3.4;

43. }

44. public override double Area()

45. {

46. return Height * Width;

47. }

48. }

49.

50. class Program

51. {

52. static void Main(string[] args)

53. {

54.

55. Drawing circle = new Circle();

56. Console.WriteLine("Area :" + circle.Area());

57.

58. Drawing square = new Square();

59. Console.WriteLine("Area :" + square.Area());

60.

61. Drawing rectangle = new Rectangle();

62. Console.WriteLine("Area :" + rectangle.Area());

63. }

64. }

The compiler requires an Area() method and it compiles successfully but the right version of the Area() method is not being determined at compile time but determined at runtime. Finally the overriding methods must have the same name and signature (number of parameters and type), as the virtual or abstract method defined in the base class method and that it is overriding in the derived class.

20. ASP.NET Application & PAGE Life Cycle

https://www.guru99.com/asp-net-intro-life-cycle-hello.html

https://www.tutorialspoint.com/asp.net/asp.net_life_cycle.htm

What is ASP.Net Page Lifecycle?

When an ASP.Net page is called, it goes through a particular lifecycle. This is done before the response is sent to the user. There are series of steps which are followed for the processing of an ASP.Net page.

Let's look at the various stages of the lifecycle of an ASP.Net web page.

ASP.Net - Intro, Life Cycle & Hello World Program

Following are the different stages of an ASP.NET page:

· Page request - When ASP.NET gets a page request, it decides whether to parse and compile the page, or there would be a cached version of the page; accordingly the response is sent.

· Starting of page life cycle - At this stage, the Request and Response objects are set. If the request is an old request or post back, the IsPostBack property of the page is set to true. The UICulture property of the page is also set.

· Page initialization - At this stage, the controls on the page are assigned unique ID by setting the UniqueID property and the themes are applied. For a new request, postback data is loaded and the control properties are restored to the view-state values.

· Page load - At this stage, control properties are set using the view state and control state values.

· Validation - Validate method of the validation control is called and on its successful execution, the IsValid property of the page is set to true.

· Postback event handling - If the request is a postback (old request), the related event handler is invoked.

· Page rendering - At this stage, view state for the page and all controls are saved. The page calls the Render method for each control and the output of rendering is written to the OutputStream class of the Response property of page.

· Unload - The rendered page is sent to the client and page properties, such as Response and Request, are unloaded and all cleanup done.

21. ASP.NET Application Life Cycle

The application life cycle has the following stages:

· User makes a request for accessing application resource, a page. Browser sends this request to the web server.

· A unified pipeline receives the first request and the following events take place:

o An object of the class ApplicationManager is created.

o An object of the class HostingEnvironment is created to provide information regarding the resources.

o Top level items in the application are compiled.

· Response objects are created. The application objects such as HttpContext, HttpRequest and HttpResponse are created and initialized.

· An instance of the HttpApplication object is created and assigned to the request.

· The request is processed by the HttpApplication class. Different events are raised by this class for processing the request.

22. ASP.NET MVC Application & PAGE Life Cycle

https://www.dotnettricks.com/learn/mvc/aspnet-mvc-request-life-cycle

https://www.tutorialspoint.com/asp.net_mvc/asp.net_mvc_life_cycle.htm

1. Routing

Asp.net Routing is the first step in MVC request cycle. Basically it is a pattern matching system that matches the request’s URL against the registered URL patterns in the Route Table. When a matching pattern found in the Route Table, the Routing engine forwards the request to the corresponding IRouteHandler for that request. The default one calls the MvcHandler. The routing engine returns a 404 HTTP status code against that request if the patterns is not found in the Route Table.

https://dotnettricks.blob.core.windows.net/img/mvc/mvcrequestcycle.png

When application starts at first time, it registers one or more patterns to the Route Table to tell the routing system what to do with any requests that match these patterns. An application has only one Route Table and this is setup in the Global.asax file of the application.

1.   public static void RegisterRoutes(RouteCollection routes)

2.   {

3.  routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

4.   routes.MapRoute( "Default", // Route name

5.   "{controller}/{action}/{id}", // URL with parameters

6.   new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults

7.   );

8.  }

2. Mvc Handler

The MvcHandler is responsible for initiating the real processing inside ASP.NET MVC. MVC handler implements IHttpHandler interface and further process the request by using ProcessRequest method as shown below:

1.  protected internal virtual void ProcessRequest(HttpContextBase httpContext)

2.  {

3.   SecurityUtil.ProcessInApplicationTrust(delegate {

4.   IController controller;

5.   IControllerFactory factory;

6.   this.ProcessRequestInit(httpContext, out controller, out factory);

7.   try

8.   {

9.   controller.Execute(this.RequestContext);

10.    }

11.    finally

12.    {

13.    factory.ReleaseController(controller);

14.    }

15.    });

16.   }

3. Controller

As shown in above code, MvcHandler uses the IControllerFactory instance and tries to get a IController instance. If successful, the Execute method is called. The IControllerFactory could be the default controller factory or a custom factory initialized at the Application_Start event, as shown below:

1.  protected void Application_Start()

2.  {

3.   AreaRegistration.RegisterAllAreas();

4.   RegisterRoutes(RouteTable.Routes);

5.   ControllerBuilder.Current.SetControllerFactory(new CustomControllerFactory());

6.  }

4. Action Execution

Once the controller has been instantiated, Controller's ActionInvoker determines which specific action to invoke on the controller. Action to be execute is chosen based on attributes ActionNameSelectorAttribute (by default method which have the same name as the action is chosen) and ActionMethodSelectorAttribute(If more than one method found, the correct one is chosen with the help of this attribute).

5. View Result

The action method receives user input, prepares the appropriate response data, and then executes the result by returning a result type. The result type can be ViewResult, RedirectToRouteResult, RedirectResult, ContentResult, JsonResult, FileResult, and EmptyResult.

6. View Engine

The first step in the execution of the View Result involves the selection of the appropriate View Engine to render the View Result. It is handled by IViewEngine interface of the view engine. By default Asp.Net MVC uses WebForm and Razor view engines. You can also register your own custom view engine to your Asp.Net MVC application as shown below:

1.  protected void Application_Start()

2.  {

3.   //Remove All View Engine including Webform and Razor

4.   ViewEngines.Engines.Clear();

5.   //Register Your Custom View Engine

6.   ViewEngines.Engines.Add(new CustomViewEngine());

7.   //Other code is removed for clarity

8.  }

7. View

Action method may returns a text string,a binary file or a Json formatted data. The most important Action Result is the ViewResult, which renders and returns an HTML page to the browser by using the current view engine.

23. Top MVC question ?

https://www.tutorialspoint.com/mvc_framework/mvc_framework_interview_questions.htm

https://tutorialslink.com/Articles/Top-40-Most-Asked-Aspnet-MVC-Interview-Questions-and-Answers/56

https://www.codeproject.com/Articles/556995/ASP-NET-MVC-interview-questions-with-answers

https://medium.com/dot-net-tutorial/top-50-asp-net-mvc-interview-questions-with-answers-1fd9b1638c61

24. Abstract class

An Abstract class is an incomplete class or special class we can't instantiate. We can use an Abstract class as a Base Class. An Abstract method must be implemented in the non-Abstract class using the override keyword. After overriding the abstract method is in the non-Abstract class. We can derive this class in another class and again we can override the same abstract method with it.

Features:

An abstract class can inherit from a class and one or more interfaces.
An abstract class can implement code with non-Abstract methods.
An Abstract class can have modifiers for methods, properties etc.
An Abstract class can have constants and fields.
An abstract class can implement a property.
An abstract class can have constructors or destructors.
An abstract class cannot be inherited from by structures.
An abstract class cannot support multiple inheritance.

Example 1:

#region

    //An abstract calss can inherit from a class and one or more interfaces.

    interface IVendorTransDetails
    {
        void getVendorID();
    }
    interface IClaimsTracker
    {
        void getSeqID();
    }
    class ClaimsMaster
    {
        string getDCNNO()
        {
            return "PC20100308A00005";
        }
    }

Example 2:

abstract class Abstract : ClaimsMaster, IClaimsTracker, IVendorTransDetails
{
    //Here we should implement modifiers oterwise it throws complie-time error
    public void getVendorID()
    {
        int s = new int();
        s = 001;
        Console.Write(s);
    }

    public void getSeqID()
    {
        int SeqID = new int();
        SeqID = 001;
        Console.Write(SeqID);
    }
}
#endregion

25. Virtual.

A virtual method can be redefined. The virtual keyword designates a method that is overridden in derived classes. We can add derived types without modifying the rest of the program. The runtime type of objects thus determines behavior.

This program introduces 2 classes. Class A has a public virtual method called Test. Class B, meanwhile, derives from class A and it provides a public override method called Test as well.

Tip: The virtual modifier tells the compiler that when any class derived from class A is used, an override method should be called.

Override

Based on: .NET (2018)

C# program that introduces virtual method

using System;

class A

    public virtual void Test()

        Console.WriteLine("A.Test");

class B : A

    public override void Test()

        Console.WriteLine("B.Test");

class Program

    static void Main()

        // Compile-time type is A.

        // Runtime type is A as well.

        A ref1 = new A();

        ref1.Test();

        // Compile-time type is A.

        // Runtime type is B.

        A ref2 = new B();

        ref2.Test();

Indus net Interview Question:

1. Abstraction

2. Encapsulation

3. Interface

4. Polymorphism type

5. Virtual class

6. Overriding

7. Overloading

8. How to implement encapsulation in c#

9. Asp .Net life cycle

10. MVC life cycle

11. MVC definition

12. MVC section (true / false )

13. Html render partial and html partial deferent.

14. Session handling in MVC

15. Filter types. Action filter work process

16. What is Routing

17. Asp .Net viewstate

SQL

1. Difference between Varchar and NVarchar

2. Delete duplicate row query

3. 2^nd highest salary output

4. Group by

5. Having clause

6. Temp table and type table deferent

7. Cursor

8. Index

9. IIS server

10. $each function in javascript

11. Web garden

12. Worker process

13. Application poll

Answer:-

1. Abstract class

2. Encapsulation is implemented by using access specifies. An access specifies defines the scope and visibility of a class member. C# supports the following access specifies −

Public

Private

Protected

Internal

Protected internal

3. What is Interface?

An interface looks like a class, but has no implementation. The only thing it contains are declarations of events,

Indexers, methods and/or properties. The reason interfaces only provide declarations is because they are inherited by

structs and classes, that must provide an implementation for each interface member declared.

4. Difference between Html.Partial() and Html.RenderPartial() in ASP.NET MVC

Html.Partial()	Html.RenderPartial()
Html.Partial returns html string.	Html.RenderPartial returns void.
Html.Partial injects html string of the partial view into main view.	Html.RenderPartial writes html in response stream.
Performance is slow.	Perform faster than HtmlPartial().
Html.Partial() need not to be inside the braces.	Html.RenderPartial must be inside braces @{ }.

5. Types of Filters

ASP.NET MVC framework supports the following action filters −

· Action Filters − Action filters are used to implement logic that gets executed before and after a controller action executes.

· Authorization Filters − Authorization filters are used to implement authentication and authorization for controller actions.

· Result Filters − Result filters contain logic that is executed before and after a view result is executed. For example, you might want to modify a view result right before the view is rendered to the browser.

· Exception Filters − Exception filters are the last type of filter to run. You can use an exception filter to handle errors raised by either your controller actions or controller action results. You also can use exception filters to log errors.

6. Viewstate in asp net c#

View State is the method to preserve the Value of the Page and Controls between round trips. It is a Page-Level State Management technique.

View State is turned on by default and normally serializes the data in every control on the page regardless of whether it is actually used during a post-back.

7. What is the difference between SQL server varchar and nvarchar data type?

VARCHAR Data type: -
- Non Unicode variable length character data type.
-Takes 1 byte per character.
-Used to store data which contains non unicode characters.
-Uses 1 byte per character + 2 extra bytes for storing offset.
-Can store maximum of 8000 non unicode characters.

NVARCHAR Data type:-
-Unicode variable length character data type.
-Takes 2 bytes per character.
-Used to store both unicode(like Japanese, Korean etc.) and non unicode characters.
-Uses 2 bytes per character + 2extra bytes for storing offset.
-Can store maximum of 4000 unicode characters/non unicode characters.

8. Delete duplicate row query?

DELETE FROM Studemt_tbl WHERE Id IN

(

SELECT MIN(Id) FROM Studemt_tbl

GROUP BY Name HAVING COUNT(Id)>1

)

9. 2^nd highest salary output query?

SELECT MAX(Roll) as SndRoll From Studemt_tbl WHERE Roll < ( SELECT Max(Roll) FROM Studemt_tbl);

10. What is the Group by Clause?

The GROUP BY clause is a SQL command that is used to group rows that have the same values.

The GROUP BY clause is used in the SELECT statement .Optionally it is used in conjunction with aggregate functions to produce summary reports from the database.

Example: SELECT `gender`,COUNT(`membership_number`) FROM `members` GROUP BY `gender`;

11. The HAVING Clause enables you to specify conditions that filter which group results appear in the results.

SELECT column_name(s) FROM table_name WHERE condition GROUP BY column_name(s) HAVING condition ORDER BY column_name(s);

SELECT COUNT(CustomerID), Country FROM Customers GROUP BY Country HAVING COUNT(CustomerID) > 5;

12. Local Temporary Tables

Local temporary tables are the tables stored in tempdb. Local temporary tables are temporary tables that are available only to the session that created them. These tables are automatically destroyed at the termination of the procedure or session. They are specified with the prefix #, for example #table_name and these temp tables can be created with the same name in multiple windows. Local temporary table name is stared with hash ("#") sign.

13. Cursor: A cursor is a pointer to this context area. PL/SQL controls the context area through a cursor. A cursor holds the rows (one or more) returned by a SQL statement. The set of rows the cursor holds is referred to as the active set.

You can name a cursor so that it could be referred to in a program to fetch and process the rows returned by the SQL statement, one at a time. There are two types of cursors −

· Implicit cursors

· Explicit cursors

14. Index in SQL :

An index helps to speed up SELECT queries and WHERE clauses, but it slows down data input, with the UPDATE and the INSERT statements. Indexes can be created or dropped with no effect on the data.

· Indexes should not be used on small tables.

· Tables that have frequent, large batch updates or insert operations.

· Indexes should not be used on columns that contain a high number of NULL values.

· Columns that are frequently manipulated should not be indexed.

Types of indexes:

· Clustered. Clustered indexes sort and store the data rows in the table or view based on their key values. These are the columns included in the index definition. ...

· Nonclustered. Nonclustered indexes have a structure separate from the data rows.

15. Internet Information Server

Internet Information Server (IIS) is one of the most popular web servers from Microsoft that is used to host and provide Internet-based services to ASP.NET and ASP Web applications. A web server is responsible for providing a response to requests that come from users. When a request comes from client to server IIS takes that request from users and process it and send response back to users

16. $.each($('.productDescription'), function (index, value) {

console.log(index + ':' + $(value).text());

});

17. Web garden is a scenario in which a single machine has multiple asp.net worker processes running simultaneously. A web garden is utilized on a multi-core web server. To achieve more robust execution and processing of the C# ASP .NET web application threads, each worker process within the application pool would execute on an individual processor. It is created within Internet Information Services (IIS) by creating an application pool, selecting the Performance tab, and under the "Web Garden" section, setting the maximum number of worker processes to a value greater than 1.

Advantages of Web Garden

It increases application availability
Less consumption of physical space with better capacity
Optimum utilization of processes running on multiple processors located in a single server
Finer grained partitioning of Web servers help to control the administration of web sites individually, though they reside on the same server
With the concept of Processor affinity (binding the application to processor with the help of CPU masks), applications can be swapped out and restarted on the fly.

18. Worker Process: Worker Process (w3wp.exe) runs the ASP.Net application in IIS. This process is responsible for managing all the request and response that are coming from the client system. All the ASP.Net functionality runs under the scope of the worker process. When a request comes to the server from a client worker process is responsible for generating the request and response. In a single word, we can say worker process is the heart of ASP.NET Web Application which runs on IIS.

Application Pool: Application pool is the container of the worker process. Application pools are used to separate sets of IIS worker processes that share the same configuration. Application pools enable a better security, reliability, and availability for any web application. The worker process serves as the process boundary that separates each application pool so that when one worker process or application is having an issue or recycles, other applications or worker processes are not affected. This makes sure that a particular web application doesn’t impact other web application as they are configured into different application pools.

Constant

Constant fields or local variables must be assigned a value at the time of declaration and after that they cannot be modified. By default constant are static, hence you cannot define a constant type as static.

Constants are declared using a "const" keyword.

ReadOnly

A readonly field can be initialized either at the time of declaration or with in the constructor of same class. Therefore, readonly fields can be used for run-time constants.

Types of Filters in ASP.NET MVC and their Sequence of Execution

There are five types of Filters in ASP.NET MVC 5:

Authentication Filters:

Authentication filter runs before any other filter or action method. Authentication confirms that you are a valid or invalid user. Action filters implements the IAuthenticationFilter interface.
Authorization Filters:

The AuthorizeAttribute and RequireHttpsAttribute are the examples of Authorization Filters. Authorization Filters are responsible for checking User Access; these implement the IAuthorizationFilterinterface in the framework. These filters used to implement authentication and authorization for controller actions. For example, the Authorize filter is an example of an Authorization filter.
Action Filters:

Action Filter is an attribute that you can apply to a controller action or an entire controller. This filter will be called before and after the action starts executing and after the action has executed.

Action filters implement the IActionFilter interface that have two methods OnActionExecuting and OnActionExecuted. OnActionExecuting runs before the Action and gives an opportunity to cancel the Action call. These filters contain logic that is executed before and after a controller action executes, you can use an action filter, for instance, to modify the view data that a controller action returns.
Result Filters:

The OutputCacheAttribute class is an example of Result Filters. These implement the IResultFilter interface which like the IActionFilter has OnResultExecuting and OnResultExecuted. These filters contains logic that is executed before and after a view result is executed. Like if you want to modify a view result right before the view is rendered to the browser.
ExceptionFilters:

The HandleErrorAttribute class is an example of ExceptionFilters. These implement the IExceptionFilter interface and they execute if there are any unhandled exceptions thrown during the execution pipeline. These filters can be used as an exception filter to handle errors raised by

6. A practical example:

7. 1.You have an iframe that has a youtube player.

8. 2.You request some videos to play from youtube data api (CORS, could be JSONP, XHR or whatever).

9. 3.You now pass a cross-domain message to the iframe to start playing any of the video you requested in step #2.

10. From Reference: http://stackoverflow.com/a/8186722

11. Also from WikiPedia definition:

12. Cross-origin resource sharing (CORS) is a mechanism that allows many resources (e.g., fonts, JavaScript, etc.) on a web page to be requested from another domain outside the domain from which the resource originated.[1] In particular, JavaScript's AJAX calls can use the XMLHttpRequest mechanism. Such "cross-domain" requests would otherwise be forbidden by web browsers, per the same-origin security policy. CORS defines a way in which the browser and the server can interact to determine whether or not to allow the cross-origin request.[2] It is more useful than only allowing same-origin requests, but it is more secure than simply allowing all such cross-origin requests.

What is a Callback?

Simply put: A callback is a function that is to be executed after another function has finished executing — hence the name ‘call back’.

Ready Function in JQuery ?

When using another JavaScript library, we may wish to call $.noConflict() to avoid namespace difficulties. When this function is called, the $ shortcut is no longer available, forcing us to write jQuery each time we would normally write $. However, the handler passed to the .ready() method can take an argument, which is passed the global jQuery object.

State Management in Asp.net MVC?

HTTP is a stateless protocol, i.e., each HTTP request does not know about the previous request. If you are redirecting from one page to another page, then you have to maintain or persist your data so that you can access it further. To do this, there were many techniques available in ASP.NET like ViewState, SessionState, ApplicationState etc.

ASP.NET MVC also provides state management techniques that can help us to maintain the data when redirecting from one page to other page or in the same page after reloading. There are several ways to do this in ASP.NET MVC -

Hidden Field
Cookies
Query String
ViewData
ViewBag
TempData

Difference between normal application and mvc application ?

ASP.NET MVC vs Web Forms

	ASP.NET MVC	Web Forms
1	MVC focuses on separation of concern, i.e., there is no any fixed code behind page for every view. A view can be called from multiple action.	Web form based on functions and page behind code, i.e., there is code behind page for each view. You have to write code in that class related to this view only.
2	First request comes to controller and action, then view gets called.	First request comes to Page (View) then it will go to code behind page.
3	MVC provides HTML Helpers to create form controls. This is optional. You can use simple HTML controls also.	For everything in webforms, you have a server control.
4	There is no ViewState for state management in View.	Viewstate is used to maintain state of form in view. This also makes page heavy.
5	Good for SEO friendly urls. No need to map to existing physical files.	Earlier, this feature was not available in Webforms but now it is available. Although it is not that easy and it is optional.
6	We create partial views for reusable views.	We create user controls for reusable view or control.
7	It is very easy to use jquery and JavaScripts. Using CSS is also easy	It is a little difficult to use jquery and JavaScripts in web forms. It provides themes and it is difficult to manage design of server controls.
8	Maintaining Id of form controls are easy and you can fully control them when working with Jquery.	It is difficult to mange Id of server controls, you don't know adject id of server controls most of the time. Specially working with user controls.

What Is Data annotation?

Data validation is a key aspect for developing web application. In Asp.net MVC, we can easily apply validation to web application by using Data Annotation attribute classes to model class. Data Annotation attribute classes are present in System.ComponentModel.DataAnnotations namespace and are availlable to Asp.net projects like Asp.net web application & website, Asp.net MVC, Web forms and also to Entity framework orm models.

Data Annotations help us to define the rules to the model classes or properties for data validation and displaying suitable messages to end users.

Data Annotation Validator Attributes:

· DataType

· Specify the datatype of a property

· DisplayName

· specify the display name for a property.

· DisplayFormat

· specify the display format for a property like different format for Date proerty.

· Required

· Specify a property as required.

· ReqularExpression

· validate the value of a property by specified regular expression pattern.

· Range

· validate the value of a property with in a specified range of values.

· StringLength

· specify min and max length for a string property.

· MaxLength

· specify max length for a string property.

· Bind

· specify fields to include or exclude when adding parameter or form values to model properties.

· ScaffoldColumn

· specify fields for hiding from editor forms.

About JsonResult format and its properties?

The JSON format is an open standard format. The format of data looks very easy to understand and the data objects consist of attribute-value pairs.

ContentEncoding: It helps to indicate the content encoding type, the default encoding for JSON is UTF-8.

ContentType: It helps to indicate the content type. The default content type for JSON is application/json; charset=utf-8.

Note: ContentType and ContentEncoding are not necessary to mention when sending the data in JSON format as the HTTP headers are having a responsibility to tell the recipient what kind of content they're dealing with.

Data: This indicates what the content data is, that means what you will send in JSON format.

JsonRequestBehavior: This property has two options. Those are AllowGet and DenyGet. The default option is DenyGet. When you send data in JSON format, using Get Request, it's necessary to specify the property as AllowGet otherwise it shows the error as “The request would be blocked since the JSON data is considered as sensitive data information”.

MaxJsonLength: This helps to get or set the maximum JSON content length that you will send. The default value for this is 2097152 characters, that is equal to 4 MB of Unicode string data. You can even increase the size based if needed, for that you will get an idea later in this article.

RecursionLimit: Indicates the constraining number of object levels to process. The default value is 100. It means you can serialize the objects that are nested to a depth of 100 objects referencing each other. In a general scenario, the default limit 100 is obviously sufficient when you deal with a JsonResult so there is no need to increase it even though you have the option to increase the limit if required.

Filters run in the following order:

There are the following types of filters that can be implemented to inject custom processing logic.

Authorization filter
Action filter
Result filter
Exception filter

Create custom view engine in MVC application

There are various third-party view engines available like Nhaml (pronounced enamel), spark, Brail, nVelocity but the most famous one is Razor used .cshtml and .vbhtml files to recognize views to render as simple HTML.

You can create your own view engine and even use that with other view engines in one application. To use your custom view engine, you have to register your view engine in global.aspx file.

OLTP (online transaction processing)

OLTP (online transaction processing) is a class of software programs capable of supporting transaction-oriented applications on the Internet.

Typically, OLTP systems are used for order entry, financial transactions, customer relationship management (CRM) and retail sales. Such systems have a large number of users who conduct short transactions. Database queries are usually simple, require sub-second response times and return relatively few records.

What is RDBMS?

RDBMS stands for Relational Database Management System. RDBMS is the basis for SQL, and for all modern database systems like MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access.

A Relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd.

Properties of Relational Table?

Relational tables have six properties: 1. Values are atomic. 2. Column values are of the same kind. 3. Each row is unique. 4. The sequence of columns is insignificant. 5. The sequence of rows is insignificant. 6. Each column must have a unique name.

Difference between primary key and unique key in sql server?

Primary Key

Primary key cannot have a NULL value.
Each table can have only one primary key.
By default, Primary key is clustered index, and the data in database table is physically organized in the sequence of clustered index.
Primary key can be related to another tables as a Foreign Key.
We can generate ID automatically with the help of Auto Increment field. Primary key supports Auto Increment value.
We can define Primary key constraint on temporary table and table variable.
We can't delete primary key value from the parent table which is used as a foreign key in child table. To delete we first need to delete that primary key value from the child table.

Unique Key

Unique Constraint may have a NULL value.
Each table can have more than one Unique Constraint.
By default, Unique key is a unique non-clustered index.
Unique Constraint can not be related with another table's as a Foreign Key.

Foreign Key

Foreign key is a field in the table that is Primary key in another table.
Foreign key can accept multiple null value.
Foreign key do not automatically create an index, clustered or non-clustered. You can manually create an index on foreign key.
We can have more than one foreign key in a table.
Foreign keys do not automatically create an index, clustered or non-clustered. You must manually create an index on foreign keys.
There are actual advantages to having a foreign key be supported with a clustered index, but you get only one per table. What's the advantage? If you are selecting the parent plus all child records, you want the child records next to each other. This is easy to accomplish using a clustered index.
Having a null foreign key is usually a bad idea instead of NULL referred to as "orphan record".
We can’t define foreign key constraint on temporary table or table variable.
We can delete the foreign key value from the child table even though that refers to the primary key of the parent table.

Sk Habib

Thursday 17 January 2019

Asp .Net MVC Interview questions.