Happy New Year 2022

IQ

1.  What is C#
2. Types of comment in C#
3. Object in C#
4. What is the .NET framework
5. components of .NET
6. What is OOP
7. difference between Array and ArrayList
8. Control Statement in C#
9. Classes in C#
10. abstract class and interface in .net
11. Constructors ?
12. Assembly?
13. Private/PublicAssembly?
14. MVC (Model, View, Controller)
15. Languages Supported by .net platform
16. Project details
17. Some logics (C#/.net)
18. Viewbag VS view data
19. Action filters
20. Authorized filter BTW action filter
21. Extension methods
22. async,await
23. solid principles
24. dependency injection
25. singleton design pattern
26. delegate types- func,predicate delegate
27. abstract class vs interface
28. sealed class
29. caching Technics
30. use of using 
31. GC.collect vs finalize vs Dispose
32. What tecnics are using for generating tokens
33. Which one is faster DBfirst or code first
34. what is bundle config and CDN
35. what is application object and session object and differenece
36. abstarct class and interface
37. IIS request processing
38. ref vs out
39. status codes-403,200,500
40. what render
41. web api testing tecnincs
42. difference web api,wcf.
43. without using try block how to handle exceptions
44. verbs in web api
45. what are contracts
46. diffbetween service contract and message contract
47. solid principles
48. How to Install certificates in IIS
49. Passport authentication works
50. Difference between Webservice/WCF
51. Webapi Token types
52. Code first/DB first approach Which one better
53. Where configure endpoints in WCF
54. Differenec between XML/JSON
55. Bundle config/CDN which one is better.
56. Authentication and Authorization in Web API
57. Secure a Web API with Individual Accounts in Web API 2.2
58. External Authentication Services with Web API (C#)
59. Preventing Cross-Site Request Forgery (CSRF) Attacks in Web API
60. Enabling Cross-Origin Requests in Web API 2
61. Authentication Filters in Web API 2
62. Basic Authentication in Web API
63. Forms Authentication in Web API
64. Integrated Windows Authentication
65. Working with SSL

React JS IQ

React JS:

Remove duplicate characters in array of elements

var sandwiches = ['turkey', 'ham', 'turkey', 'tuna', 'pb&j', 'ham', 'turkey', 'tuna'];

var deduped = Array.from(new Set(sandwiches));

// Logs ["turkey", "ham", "tuna", "pb&j"]

console.log(deduped);

• given word last letter should be capital.
• Cloure function

          Closures are inner functions that have access to the outer function’s variables and parameters. Even after the outer function’s execution is finished, the inner functions have access to the variables in the outer function. Closures are everywhere in JavaScript and you’ve probably been using it even if you have not realised it yet.

• diff class component, functional component

Functional Components	Class Components
A functional component is just a plain JavaScript function that accepts props as an argument and returns a React element.	A class component requires you to extend from React. Component and create a render function which returns a React element.
There is no render method used in functional components.	It must have the render() method returning HTML
Also known as Stateless components as they simply accept data and display them in some form, that they are mainly responsible for rendering UI.	Also known as Stateful components because they implement logic and state.
React lifecycle methods (for example, componentDidMount) cannot be used in functional components.	React lifecycle methods can be used inside class components (for example, componentDidMount).

• Error Handling in React.
• how to give generic exception and display the message
• error boundaris
• what is call back hell function
• what is non blocking io---asyncronous call
• what is stright mode
• Differenec Virtual dom and Real dom.
• react life cycle
• what is promise unchining,promise.all-- promise is asyncronous call
• diff let,var,const
• what is closur function,nested function
• basic ES6 features- let and var,promise,iterator
• How to deploy React application
• React Router types how it works,nested routes
• What is Arrow function,uses
• spread operator
• what is generator
• what is hooks- use memo,use context,use effect
• How redux works
• diff element and component
• how to prevent rerendering-- using pure componentd or use memo
• React application performence.
• synthatic events.
• what is controlled components
• how to set initial state in Redux
• Store in Redux
• How many types are Reducers

• what is Data binding
• What is context API

React JS questions

1. Remove duplicate characters in array of elements
2. Given word last letter should be capital.
3. Closure function
4. diff class component, functional component
5. Error Handling in React.
6. how to give generic exception and display the message
7. error boundaris
8. what is call back hell function
9. what is non blocking io---asyncronous call
10. what is stright mode
11. Differenec Virtual dom and Real dom.
12. react life cycle
13. what is promise unchining,promise.all-- promise is asyncronous call
14. diff let,var,const
15. what is closur function,nested function
16. basic ES6 features- let and var,promise,iterator
17. How to deploy React application
18. React Router types how it works,nested routes
19. What is Arrow function,uses
20. spread operator
21. what is generator
22. what is hooks- use memo,use context,use effect
23. How redux works
24. diff element and component
25. how to prevent rerendering-- using pure componentd or use memo
26. React application performence.
27. synthatic events.
28. what is controlled components
29. how to set initial state in Redux
30. Store in Redux
31. How many types are Reducers
32. Redux life cycle
33. Diff State and props
34. what is Data binding
35. What is context API

Javascript:

1. diff betewen Null and undefined
2. typeof(null)
3. Event bubling
4. Define Json array
5. how to detect object like mobile or tab-- using responsiveness media query
6. purpose of encoding url
7. what is decorater
8. copy an object in javascript-- object

1. Remove duplicate characters in array of elements

• const uniqueNames = Array.from(new Set(names));

1. Given word last letter should be capital.

• const cap = str => str
                       .split(' ')
                       .map(x => (
                           x.length === 1 ? 
                               x.toUpperCase() : 
                              `${x[0].toUpperCase()}${x.slice(1,-1)}${x[x.length -1].toUpperCase()}`)
                       )  
                       .join(' ')
  
  console.log(cap("a quick brown fox"))

• diff class component, functional component

• There is no render method used in functional components.
  
  React lifecycle methods (for example, componentDidMount) cannot be used in functional components.
  It must have the render() method returning HTML
  React lifecycle methods can be used inside class components (for example, componentDidMount).

IQ

1. What tecnics are using for generating tokens
2. Which one is faster DBfirst or code first
3. what is bundle config and CDN
4. what is application object and session object and differenece
5. abstarct class and interface
6. IIS request processing
7. status codes-403,200,500
8. what render
9. web api testing tecnincs
10. difference web api,wcf.
11. without using try block how to handle exceptions
12. verbs in web api
13. what are contracts
14. diffbetween service contract and message contract
15. solid principles
16. How to Install certificates in IIS
17. Passport authentication works
18. Difference between Webservice/WCF
19. Webapi Token types
20. Code first/DB first approach Which one better
21. Where configure endpoints in WCF
22. Differenec between XML/JSON
23. Bundle config/CDN which one is better

IQ

1. What is Base class for Asp.net
2. Authentication and Authorization config settings
3. Forms Authentication config settings
4. Difference between Datareader/Dataset, Handlers/Modules
5. How to make web api calls asynchronously.
6.  How many ways to pass data to View to controller
7. Merge key word in sql.
8. CTE main purpose
9. Solid principles
10. What type of code in Pre render
11. CI/CD process.

1) Given number is even or odd in c# without using condition

using System;

class test 

{

  static void Main() 

   {

    string[] arr = {"Even", "Odd"};

      

    Console.Write("Enter the number: ");

     

    string val;

    val = Console.ReadLine();

    int no = Convert.ToInt32(val);

 

    Console.WriteLine(arr[no%2]);

  }

}

2) How can Select Only last Row of the Table Using Sql

   SELECT TOP 1 * FROM MyTable ORDER BY MyColumn ASC

3) scaling in sql server

  Horizontal and vertical scaling

   The following figure shows the horizontal and vertical dimensions of scaling, which are the basic ways the elastic databases can be scaled.

  Horizontal scaling refers to adding or removing databases in order to adjust capacity or overall performance, also called "scaling out". 

Sharding, in which data is partitioned across a collection of identically structured databases, is a common way to implement horizontal scaling.

Vertical scaling refers to increasing or decreasing the compute size of an individual database, also known as "scaling up."

Most cloud-scale database applications use a combination of these two strategies. For example, a Software as a Service application may use horizontal scaling to provision new end-customers and vertical scaling to allow each end-customer's database to grow or shrink resources as needed by the workload.

Horizontal scaling is managed using the Elastic Database client library.

Vertical scaling is accomplished using Azure PowerShell cmdlets to change the service tier, or by placing databases in an elastic pool.

Cons of JavaScript

1. Client-side Security

Since the JavaScript code is viewable to the user, others may use it for malicious purposes. These practices may include using the source code without authentication. Also, it is very easy to place some code into the site that compromises the security of data over the website.

2. Browser Support

The browser interprets JavaScript differently in different browsers. Thus, the code must be run on various platforms before publishing. The older browsers don’t support some new functions and we need to check them as well.

3. Lack of Debugging Facility

Though some HTML editors support debugging, it is not as efficient as other editors like C/C++ editors. Also, as the browser doesn’t show any error, it is difficult for the developer to detect the problem.

4. Single Inheritance

JavaScript only supports single inheritance and not multiple inheritance. Some programs may require this object-oriented language characteristic.

5. Rendering Stopped

A single code error can stop the rendering of the entire JavaScript code on the website. To the user, it looks as if JavaScript was not present. However, the browsers are extremely tolerant of these errors.

Difference between inline query and stored procedure

1.Stored procedures are strored in a pre complied form.That is once a Stored procedure is executed, the compiled code is used in subsequent calls. This is not possible with inline queries.

2.Stored procedures reduces network traffic. 
Since Stored procedures are stored in the server, only the name of Stored procedure is required to pass to the server. But in the case of inline queries , the complete query has to be passed to the server. So inline queries will increase network traffic when the queries are very large.

3.Stored procedures support Deferred Name Resolution.That is we can create stored procedures for objects(eg:- tables) which are not yet created ( and will be creating in the near future)

4.Stored procedures prevents SQL Injection Errors.

5.By using Stored procedures we can seperate all the queries from the Business logic code.
Therefore we can create a seperate layer.
But while writing inline queries , all the queries have to be written (mixed up ) with the business logic code. This create problem while debugging.

6.Developers can work simultaneously while using stored procedures.
While a programmer writes business logic, another one can create stored procedures at the same time.

Features in Visual Studio

 

React JS QS

 

What is React?

React is an open-source frontend JavaScript library which is used for building user interfaces especially for single page applications. It is used for handling view layer for web and mobile apps. React was created by Jordan Walke, a software engineer working for Facebook. React was first deployed on Facebook's News Feed in 2011 and on Instagram in 2012.

What are the major features of React?

The major features of React are:

• It uses VirtualDOM instead of RealDOM considering that RealDOM manipulations are expensive.
• Supports server-side rendering.
• Follows Unidirectional data flow or data binding.
• Uses reusable/composable UI components to develop the view.

What is JSX?

JSX is a XML-like syntax extension to ECMAScript (the acronym stands for JavaScript XML). Basically it just provides syntactic sugar for the React.createElement() function, giving us expressiveness of JavaScript along with HTML like template syntax.

In the example below text inside <h1> tag is returned as JavaScript function to the render function.

class App extends React.Component {
  render() {
    return(
      <div>
        <h1>{'Welcome to React world!'}</h1>
      </div>
    )
  }
}

How to create components in React?
There are two possible ways to create a component.
Function Components: This is the simplest way to create a component. Those are pure JavaScript functions that accept props object as first parameter and return React elements:
function Greeting({ message }) {
  return <h1>{`Hello, ${message}`}</h1>

}
Class Components: You can also use ES6 class to define a component. The above function component can be written as:
class Greeting extends React.Component {
  render() {
    return <h1>{`Hello, ${this.props.message}`}</h1>
  }
}

When to use a Class Component over a Function Component?
If the component needs state or lifecycle methods then use class component otherwise use function component.However, from React 16.8 with the addition of Hooks, you could use state , lifecycle methods and other features that were only available in class component right in your function component.

What is state in React?
State of a component is an object that holds some information that may change over the lifetime of the component. We should always try to make our state as simple as possible and minimize the number of stateful components.
Let's create an user component with message state,
class User extends React.Component {
  constructor(props) {
    super(props)

    this.state = {
      message: 'Welcome to React world'
    }
  }

  render() {
    return (
      <div>
        <h1>{this.state.message}</h1>
      </div>
    )
  }
}
State is similar to props, but it is private and fully controlled by the component. i.e, It is not accessible to any component other than the one that owns and sets it.

ReactJS Interview Questions

1. What are the features of React?

JSX:  JSX is a syntax extension to JavaScript. It is used with React to describe what the user interface should look like. By using JSX, we can write HTML structures in the same file that contains JavaScript code.

Components: Components are the building blocks of any React application, and a single app usually consists of multiple components. It splits the user interface into independent, reusable parts that can be processed separately.

  

Virtual DOM: React keeps a lightweight representation of the real DOM in the memory, and that is known as the virtual DOM. When the state of an object changes, virtual DOM changes only that object in the real DOM, rather than updating all the objects.

One-way data-binding: React’s one-way data binding keeps everything modular and fast. A unidirectional data flow means that when designing a React app, you often nest child components within parent components.

High performance: React updates only those components that have changed, rather than updating all the components at once. This results in much faster web applications.

2. What is JSX?

JSX is a syntax extension of JavaScript. It is used with React to describe what the user interface should look like. By using JSX, we can write HTML structures in the same file that contains JavaScript code.

3. Can web browsers read JSX directly? 

• Web browsers cannot read JSX directly. This is because they are built to only read regular JS objects and JSX is not a regular JavaScript object 
• For a web browser to read a JSX file, the file needs to be transformed into a regular JavaScript object. For this, we use Babel

4. What is the virtual DOM?

DOM stands for Document Object Model. The DOM represents an HTML document with a logical tree structure. Each branch of the tree ends in a node, and each node contains objects.

React keeps a lightweight representation of the real DOM in the memory, and that is known as the virtual DOM. When the state of an object changes, the virtual DOM changes only that object in the real DOM, rather than updating all the objects.

5. Why use React instead of other frameworks, like Angular?

Easy creation of dynamic applications: React makes it easier to create dynamic web applications because it provides less coding and provides more functionality, whereas, with JavaScript applications, code tends to get complex very quickly.

Improved performance: React uses virtual DOM, which makes web applications perform faster. Virtual DOM compares its previous state and updates only those components in the real DOM, whose states have changed, rather than updating all the components — like conventional web applications.

Reusable components: Components are the building blocks of any React application, and a single app usually consists of multiple components. These components have their own logic and controls, and they can be reused through the application, which, in turn, dramatically reduces the development time of an application.

Unidirectional data flow: React follows a unidirectional data flow. This means that when designing a React app, we often nest child components within parent components. And since the data flows in a single direction, it becomes easier to debug errors and know where the problem occurs in an application at the moment.

Dedicated tools for easy debugging: Facebook has released a chrome extension that we can use to debug React applications. This makes the process of debugging React to web applications faster and easier.

6. What is the difference between the ES6 and ES5 standards?

These are the few instances where ES6 syntax has changed from ES5 syntax:

• Components and Function

• exports vs export

• require vs import

7. How do you create a React app?

These are the steps for creating a React app:

• Install NodeJS on the computer because we need npm to install the React library. Npm is the node package manager that contains many JavaScript libraries, including React.

• Install the create-react-app package using the command prompt or terminal.

• Install a text editor of your choice, like VS Code or Sublime Text.

8. What is an event in React?

An event is an action that a user or system may trigger, such as pressing a key, a mouse click, etc.

• React events are named using camelCase, rather than lowercase in HTML.
• With JSX, you pass a function as the event handler, rather than a string in HTML.
• <Button onPress={lightItUp} />

9. How do you create an event in React?

A React event can be created by doing the following:

10. What are synthetic events in React?

• Synthetic events combine the response of different browser's native events into one API, ensuring that the events are consistent across different browsers.
• The application is consistent regardless of the browser it is running in. Here, preventDefault is a synthetic event.

11. Explain how lists work in React

• We create lists in React as we do in regular JavaScript. Lists display data in an ordered format
• The traversal of lists is done using the map() function

12. Why is there a need for using keys in Lists?

Keys are very important in lists for the following reasons:

• A key is a unique identifier and it is used to identify which items have changed, been updated or deleted from the lists
• It also helps to determine which components need to be re-rendered instead of re-rendering all the components every time. Therefore, it increases performance, as only the updated components are re-rendered

13. What are forms in React?

React employs forms to enable users to interact with web applications.

• Using forms, users can interact with the application and enter the required information whenever needed. Form contain certain elements, such as text fields, buttons, checkboxes, radio buttons, etc
• Forms are used for many different tasks such as user authentication, searching, filtering, indexing, etc

14. How do you create forms in React?

We create forms in React by doing the following: 

The above code will yield an input field with the label Name and a submit button. It will also alert the user when the submit button is pressed. 

 

15. How do you write comments in React?

There are basically two ways in which we can write comments:

• Single-line comments

• Multi-line comments

16. What is an arrow function and how is it used in React?

• An arrow function is a short way of writing a function to React.
• It is unnecessary to bind ‘this’ inside the constructor when using an arrow function. This prevents bugs caused by the use of ‘this’ in React callbacks.

17. How is React different from React Native?

	React	React Native
Release	2013	2015
Platform	Web	Mobile – Android, iOS
HTML	Yes	No
CSS	Yes	No
Prerequisites	JavaScript, HTML, CSS	React.js

18. How is React different from Angular?

	Angular	React
Author	Google	Facebook
Architecture	Complete MVC	View layer of MVC
DOM	Real DOM	Virtual DOM
Data-Binding	Bi-directional	Uni-directional
Rendering	Client-Side	Server-Side
Performance	Comparatively slow	Faster due to Virtual DOM

ReactJS Component Questions

19. What are the components in React?

Components are the building blocks of any React application, and a single app usually consists of multiple components. A component is essentially a piece of the user interface. It splits the user interface into independent, reusable parts that can be processed separately.

There are two types of components in React:

• Functional Components: These types of components have no state of their own and only contain render methods, and therefore are also called stateless components. They may derive data from other components as props (properties).

function Greeting(props) {   return <h1>Welcome to {props.name}</h1>; }

• Class Components: These types of components can hold and manage their own state and have a separate render method to return JSX on the screen. They are also called Stateful components as they can have a state.

class Greeting extends React.Component {   render() {     return <h1>Welcome to {this.props.name}</h1>;   } }

20. What is the use of render() in React?

• It is required for each component to have a render() function. This function returns the HTML, which is to be displayed in the component.
• If you need to render more than one element, all of the elements must be inside one parent tag like <div>, <form>.

21. What is a state in React?

• The state is a built-in React object that is used to contain data or information about the component. The state in a component can change over time, and whenever it changes, the component re-renders.
• The change in state can happen as a response to user action or system-generated events. It determines the behavior of the component and how it will render.

22. How do you implement state in React?

23. How do you update the state of a component?

We can update the state of a component by using the built-in ‘setState()’ method:

24. What are props in React?

• Props are short for Properties. It is a React built-in object that stores the value of attributes of a tag and works similarly to HTML attributes.
• Props provide a way to pass data from one component to another component. Props are passed to the component in the same way as arguments are passed in a function.

25. How do you pass props between components?

26. What are the differences between state and props?

	State	Props
Use	Holds information about the components	Allows to pass data from one component to other components as an argument
Mutability	Is mutable	Are immutable
Read-Only	Can be changed	Are read-only
Child components	Child components cannot access	Child component can access
Stateless components	Cannot have state	Can have props

27. What is a higher-order component in React?

A higher-order component acts as a container for other components. This helps to keep components simple and enables re-usability. They are generally used when multiple components have to use a common logic. 

28. How can you embed two or more components into one?

We can embed two or more components into one using this method:

29. What are the differences between class and functional components?

	Class Components	Functional Components
State	Can hold or manage state	Cannot hold or manage state
Simplicity	Complex as compared to the stateless component	Simple and easy to understand
Lifecycle methods	Can work with all lifecycle methods	Does not work with any lifecycle method
Reusability	Can be reused	Cannot be reused

• Class components example:

• Functional components example:

30. Explain the lifecycle methods of components.

• getInitialState(): This is executed before the creation of the component.
• componentDidMount(): Is executed when the component gets rendered and placed on the DOM.
• shouldComponentUpdate(): Is invoked when a component determines changes to the DOM and returns a “true” or “false” value based on certain conditions.
• componentDidUpdate(): Is invoked immediately after rendering takes place.
• componentWillUnmount(): Is invoked immediately before a component is destroyed and unmounted permanently.

ReactJS Redux Interview Questions

31. What is Redux?

Redux is an open-source, JavaScript library used to manage application state. React uses Redux to build the user interface. It is a predictable state container for JavaScript applications and is used for the entire application’s state management.

32. What are the components of Redux?

• Store: Holds the state of the application.
• Action: The source information for the store.
• Reducer: Specifies how the application's state changes in response to actions sent to the store.

33. What is the Flux?

• Flux is the application architecture that Facebook uses for building web applications. It is a method of handling complex data inside a client-side application and manages how data flows in a React application.

• There is a single source of data (the store) and triggering certain actions is the only way way to update them.The actions call the dispatcher, and then the store is triggered and updated with their own data accordingly.

• When a dispatch has been triggered, and the store updates, it will emit a change event that the views can rerender accordingly.

34. How is Redux different from Flux?

SN	Redux	Flux
1.	Redux is an open-source JavaScript library used to manage application State	Flux is an architecture and not a framework or library
2.	Store’s state is immutable	Store’s state is mutable
3.	Can only have a single-store	Can have multiple stores
4.	Uses the concept of reducer	Uses the concept of the dispatcher

ReactJS Router Questions

35. What is React Router?

React Router is a routing library built on top of React, which is used to create routes in a React application. 

36. Why do we need to React Router?

• It maintains consistent structure and behavior and is used to develop single-page web applications. 
• Enables multiple views in a single application by defining multiple routes in the React application.

37. How is React routing different from conventional routing?

SN	React Routing	Conventional routing
1.	Single HTML page	Each view is a new HTML file
2.	The user navigates multiple views in the same file	The user navigates multiple files for each view
3.	The page does not refresh since it is a single file	The page refreshes every time user navigates
4.	Improved performance	Slower performance

38. How do you implement React routing?

We can implement routing in our React application using this method:

Considering we have the components App, About, and Contact in our application:

ReactJS Styling Questions

39. How do you style React components?

There are several ways in which we can style React components:

• Inline Styling

• JavaScript Object

• CSS Stylesheet

40. Explain the use of CSS modules in React.

• The CSS module file is created with the .module.css extension
• The CSS inside a module file is available only for the component that imported it, so there are no naming conflicts while styling the components.