ASP.NET Interview Questions and Answers: ASP.NET is a popular web application framework developed by Microsoft. It is widely used by developers to create dynamic and scalable web applications. If you’re a job seeker looking to get hired for an ASP.NET role or if you’re an employer looking to hire a skilled ASP.NET developer, you might want to have a look at the Top 100 ASP.NET Interview Questions and Answers. Through this article, you can get to know the ASP.NET Interview Questions for Freshers and Top ASP.NET Interview Questions and Answers
★★ Latest Technical Interview Questions ★★
ASP.NET Technical Interview Questions
These questions cover a wide range of topics and are designed to test the technical knowledge and problem-solving abilities of the candidate. Whether you are a fresher or an experienced developer, these Latest ASP.NET Interview Questions can help you prepare for your ASP.NET Technical Interview Questions and improve your chances of getting hired.
Top 100 ASP.NET Interview Questions and Answers 2023
1. What is ASP.NET and what are its key features?
- ASP.NET is a web application framework developed by Microsoft to build dynamic websites, web applications, and web services.
- Key features of ASP.NET include:
- Server-side scripting
- Built-in authentication and authorization
- Caching
- State management
- MVC (Model-View-Controller) architecture support
- AJAX (Asynchronous JavaScript and XML) support
- Cross-platform support with .NET Core
2. What are the different types of ASP.NET web applications?
- There are two main types of ASP.NET web applications:
- ASP.NET Web Forms: This is a traditional approach to building web applications with a drag-and-drop visual interface for designing pages and controls.
- ASP.NET MVC (Model-View-Controller): This is a newer approach to building web applications that separates the application into three distinct components: Model, View, and Controller.
3. What is the difference between ASP.NET Web Forms and ASP.NET MVC?
- ASP.NET Web Forms:
- Uses a drag-and-drop visual interface for designing pages and controls.
- Follows a page-centric approach to web development.
- Provides a simpler learning curve for developers new to web development.
- ASP.NET MVC:
- Separates the application into three distinct components: Model, View, and Controller.
- Follows a controller-centric approach to web development.
- Provides more control and flexibility over the application.
4. What is the syntax for defining a new variable in ASP.NET?
The syntax is:
| datatype variableName = value; |
5. What is the Model-View-Controller (MVC) design pattern?
- The Model-View-Controller (MVC) design pattern is a software architecture pattern that separates an application into three distinct components:
- Model: Represents the data and business logic of the application.
- View: Represents the user interface and presentation layer of the application.
- Controller: Acts as an intermediary between the Model and View, handling user input and updating the Model and View as necessary.
6. What is the difference between ApplicationState and SessionState in ASP.NET?
| Aspect | ApplicationState | SessionState |
|---|---|---|
| Scope | Application-wide | User-specific |
| Data | Shared among all users | Isolated for each user |
| Persistence | Stored in server memory | Stored on the server or in a cookie on the client |
| Accessibility | Can be accessed by any page or user | Can only be accessed by the user to whom it belongs |
| Lifetime | Same as the lifetime of the application | Same as the lifetime of the session |
| Usage | Global data sharing among users | Storing user-specific data |
| Example | Application version, connection strings, etc. | User login information, shopping cart contents, etc. |
7. How do you handle errors in ASP.NET?
- ASP.NET provides several ways to handle errors, including:
- Using try-catch blocks in code.
- Configuring custom error pages in web.config.
- Using the Application_Error event in Global.asax to handle unhandled exceptions.
8. What is the use of the Global.asax file in ASP.NET?
- The Global.asax file is a special file in an ASP.NET application that contains code for handling application-level events, such as Application_Start, Session_Start, and Application_Error.
9. What is the difference between Application_Start and Session_Start events?
- Application_Start: This event is fired when the application starts and is used to initialize the application, such as registering routes or configuring services.
- Session_Start: This event is fired when a new user session is started and is used to perform actions specific to that user session, such as initializing session variables.
10. How do you declare a new method in ASP.NET?
The syntax is:
| [access modifier] [return type] methodName(parameters){ code block } |
11. What is the difference between Response.Redirect and Server.Transfer?
- Response.Redirect: This method redirects the user to a new page by sending a new HTTP request to the server. It is useful for redirecting the user to a different website or page.
- Server.Transfer: This method transfers control to a different page on the server without issuing a new HTTP request. It is useful for redirecting the user to a different page within the same website.
12. What is ViewState in ASP.NET?
ViewState is a hidden field in an ASP.NET page that stores the state of the page and its controls between postbacks. It is used to maintain the state of the page and its controls across postbacks, such as when a user clicks a button or changes a value in a control.
13. What is the difference between an abstract class and an interface in ASP.NET?
| Aspect | Abstract Class | Interface |
|---|---|---|
| Implementation | Can have implementation details and fields | Only method, property, event signatures without implementation |
| Inheritance | Can extend only one abstract or concrete class | Can inherit multiple interfaces |
| Access Modifiers | Can have access modifiers for methods and fields | All members are public by default |
| Constructors | Can have constructors | No constructors |
| Multiple Inheritance | Does not support multiple inheritance | Supports multiple inheritance |
| Object Creation | Cannot be instantiated, must be inherited by a concrete class | Cannot be instantiated, must be implemented by a class |
| Method Override | Can override methods from its base class | Can be implemented by a class to provide its own implementation |
| Polymorphism | Supports polymorphism via inheritance | Supports polymorphism via implementation |
| Usage | Use when creating a base class with implementation and fields | Use when defining a set of methods or properties to be implemented by a class |
| Example | System.IO.Stream class | IDisposable interface |
14. What is the difference between ViewState and SessionState?
- ViewState: Stores the state of a single page and its controls between postbacks.
- SessionState: Stores data across multiple pages and postbacks for a single user session. It is stored on the server and is accessible from any page in the application. Unlike ViewState, SessionState is not limited to a single page and can be used to store any type of data.
15. Different types of caching in ASP.NET:
- Output Cache
- Data Cache
- Fragment Cache
- Distributed Cache
- Object Cache
16. What is the syntax for writing an if statement in ASP.NET?
The syntax is:
| if(condition){ code block } |
17. Difference between OutputCache and DataCache:
- OutputCache is used to cache the output of a page or user control, whereas DataCache is used to cache any type of data.
- OutputCache is implemented using the OutputCache directive, while DataCache is implemented using the Cache class.
18. Use of Master Pages in ASP.NET:
- Master Pages allow you to create a consistent look and feel for your website.
- They provide a template for the pages on your website, allowing you to define the common elements such as header, footer, navigation menu, etc.
- You can also define content placeholders that can be replaced by content specific to each page.
19. Difference between User Controls and Custom Controls:
- User Controls are created by combining existing controls and code in a single file, while Custom Controls are created from scratch as a separate class.
- User Controls are easier to create and maintain, while Custom Controls offer greater flexibility and can be reused across multiple projects.
20. How do you declare a new class in ASP.NET?
The syntax is:
| [access modifier] class ClassName{ class members } |
21. Difference between ValidationSummary and ValidationMessage:
- ValidationSummary displays a summary of all validation errors on a page, while ValidationMessage displays the error message next to the control that failed validation.
- ValidationSummary can display errors for multiple controls at once, while ValidationMessage is specific to a single control.
22. Use of Globalization and Localization features in ASP.NET:
- Globalization allows your website to support multiple languages and cultures, while Localization allows you to customize your website for a specific language or culture.
- Globalization includes features such as resource files, culture-specific formatting, and date and time formatting, while Localization includes features such as language-specific content and localized images.
23. What is the difference between a DataReader and a DataSet in ASP.NET?
| DataReader | DataSet |
|---|---|
| Forward-only, read-only data retrieval | In-memory, disconnected representation of data |
| Read-only access to data | Supports CRUD operations (Create, Read, Update, Delete) |
| Can handle large volumes of data with low memory usage | Can handle smaller volumes of data with higher memory usage |
| Typically used when retrieving large amounts of data from a database | Typically used when a small set of data needs to be manipulated in-memory |
| Requires an open connection to the database | Does not require an open connection to the database |
| Generally faster performance for retrieving data | Generally slower performance for retrieving data |
| Sequential access to data, row by row | Random access to data, can search and filter data |
| Requires manual management of resources | Automatically manages resources |
| Used for data streaming | Used for data manipulation |
24. Difference between ASP.NET Web API and WCF:
- ASP.NET Web API is used to build RESTful web services, while WCF is used to build both SOAP and RESTful services.
- ASP.NET Web API is simpler and more lightweight, while WCF offers more advanced features such as security and reliability.
25. Use of Dependency Injection in ASP.NET:
- Dependency Injection is a design pattern that allows you to decouple the dependencies between objects in your application.
- It allows you to create loosely-coupled components that can be easily tested and maintained.
26. Difference between Inversion of Control (IoC) and Dependency Injection (DI):
- Inversion of Control is a broader concept that refers to any situation in which an object is created by another object and then passed to it.
- Dependency Injection is a specific implementation of IoC that involves passing the dependencies of an object as constructor parameters or properties.
27. What is the syntax for creating a new object in ASP.NET?
The syntax is:
| ClassName objectName = new ClassName(); |
28. Difference between LINQ and SQL:
- LINQ is a language feature in C# that allows you to query any data source, including databases, XML files, and in-memory collections.
- SQL is a language used specifically for querying relational databases.
29. What is the difference between an ASP.NET Web API and an ASP.NET Web Service?
| ASP.NET Web API | ASP.NET Web Service |
|---|---|
| Primarily used for building RESTful services | Primarily used for building SOAP-based services |
| Can be used to build services that can be accessed by a wide range of clients including web browsers, mobile devices, and desktop applications | Can be used to build services that can be accessed by a wide range of clients including web browsers, mobile devices, and desktop applications |
| Uses HTTP as the underlying protocol, and supports features such as content negotiation, caching, and authentication | Uses SOAP as the underlying protocol, and supports features such as security, transactions, and reliability |
| Supports a wide range of media types, including XML, JSON, and binary data | Supports XML data only |
| Supports both synchronous and asynchronous communication | Supports synchronous communication only |
| Can be hosted on IIS or self-hosted in a custom process | Can be hosted on IIS or a custom process |
| Provides built-in support for creating unit tests | Provides built-in support for creating unit tests |
| Does not have built-in support for generating client-side proxies | Has built-in support for generating client-side proxies |
| Works well with JavaScript frameworks such as AngularJS and ReactJS | Can work with JavaScript frameworks, but requires additional configuration and tooling |
| Focused on HTTP-based services | Focused on SOAP-based services |
30. How do you define a namespace in ASP.NET?
The syntax is:
| namespace NamespaceName{ class members } |
31. What is the use of Bundling and Minification in ASP.NET?
Bundling and Minification are techniques used in ASP.NET to optimize the performance of web applications. Bundling is the process of combining multiple CSS and JavaScript files into a single file, while Minification is the process of removing unnecessary characters from these files to reduce their size.
Here are some of the uses of Bundling and Minification in ASP.NET:
- Improves page load time: Bundling and Minification help to reduce the number of HTTP requests made by the browser, resulting in faster page load times.
- Reduces bandwidth usage: Since the size of the files is reduced, the amount of data transferred between the server and the client is also reduced, resulting in lower bandwidth usage.
- Enhances caching: Bundling and Minification also help to improve caching by reducing the number of files that need to be cached.
- Simplifies maintenance: By combining multiple files into a single bundle, it becomes easier to manage and maintain the files in the application.
32. What is the syntax for creating an array in ASP.NET?
The syntax is:
| datatype[] arrayName = new datatype[size]; |
33. What is the difference between a static website and a dynamic website in ASP.NET?
| Static Website | Dynamic Website | |
|---|---|---|
| Content | Fixed, pre-defined content | Content generated dynamically |
| Pages | Limited pages, usually HTML or CSS files | Multiple pages created dynamically |
| Data | No database connection | May use a database for content management |
| Customization | Limited customization options | Highly customizable with user input |
| Performance | Loads faster as there is no server-side processing | Slower load times as there is server-side processing |
| Maintenance | Easy to maintain as there is no server-side processing | Requires regular maintenance due to server-side processing |
| Scalability | Limited scalability | Can be highly scalable due to the use of databases and server-side processing |
| Examples | Personal websites, small business sites with few pages | E-commerce sites, social media platforms, news websites |
34. What is Entity Framework and what are its advantages?
- Entity Framework is an ORM (Object Relational Mapping) framework that allows developers to work with databases using objects instead of SQL statements.
- Advantages of Entity Framework:
- It reduces the amount of code required to perform database operations.
- It provides a higher level of abstraction, making it easier to work with databases.
- It supports a variety of database providers.
- It enables developers to work with the database using a strongly-typed API.
35. What is the difference between Code First and Database First approach in Entity Framework?
- Code First Approach:
- Developers create the classes first and then the database schema is generated from those classes.
- This approach is useful when working with existing applications, where database schema already exists.
- Database First Approach:
- Developers start with an existing database schema and then the classes are generated from the schema.
- This approach is useful when working with new applications, where the database schema needs to be designed and created first.
36. What are the different types of Authentication in ASP.NET?
- There are several types of Authentication in ASP.NET:
- Forms Authentication
- Windows Authentication
- Passport Authentication
- Certificate Authentication
- Token Authentication
37. What is the difference between Forms Authentication and Windows Authentication?
- Forms Authentication:
- Uses a custom login page to authenticate users.
- Stores user credentials in a cookie.
- Allows developers to implement custom login/logout behavior.
- Windows Authentication:
- Uses the user’s Windows credentials to authenticate.
- Requires that the user is part of the domain or has a local user account on the server.
- Does not require a custom login page.
38. What is the difference between Authorization and Authentication in ASP.NET?
- Authentication:
- The process of verifying the identity of a user.
- Determines whether the user is allowed to access the application.
- Authorization:
- The process of verifying whether a user has permission to perform a specific action.
- Determines whether the user is allowed to perform a specific action within the application.
39. What is the use of roles in ASP.NET?
- Roles in ASP.NET are used to group users with similar permissions.
- This simplifies the process of managing user permissions and allows developers to assign permissions to groups of users instead of individual users.
40. What is the difference between Impersonation and Delegation in ASP.NET?
- Impersonation:
- Allows an application to run with the permissions of a different user.
- Used to access resources that require a higher level of permission than the current user.
- Delegation:
- Allows an application to delegate its permissions to another application.
- Used when an application needs to access resources that require permissions outside of its own scope.
41. What is the difference between Custom Authentication and OWIN Authentication Middleware in ASP.NET?
- Custom Authentication:
- Developers write custom code to authenticate users.
- Provides complete control over the authentication process.
- Can be more complex and time-consuming to implement.
- OWIN Authentication Middleware:
- Provides a framework for building authentication middleware.
- Reduces the amount of code required to implement authentication.
- Supports a variety of authentication providers.
42. What is the difference between Authorization Filters and Action Filters in ASP.NET?
- Authorization Filters:
- Used to control access to an action method.
- Executed before the action method is executed.
- Action Filters:
- Used to add additional behavior to an action method.
- Executed before and after the action method is executed.
43. How do you write a for loop in ASP.NET?
The syntax is:
| for(initialization; condition; increment/decrement){ code block } |
44. What is the difference between JavaScript and jQuery?
- JavaScript is a programming language, while jQuery is a library written in JavaScript.
- JavaScript is used to write scripts that can be executed on the client-side or server-side, while jQuery is a library of pre-written JavaScript code that simplifies common tasks in web development.
- JavaScript can be used for more complex programming tasks, while jQuery is designed for simpler tasks such as DOM manipulation, event handling, and AJAX calls.
45. What are the different types of jQuery selectors?
- The most common jQuery selectors are:
- Element selectors (e.g. $(“p”) selects all <p> elements)
- ID selectors (e.g. $(“#myId”) selects the element with id=”myId”)
- Class selectors (e.g. $(“.myClass”) selects all elements with class=”myClass”)
- Attribute selectors (e.g. $(“input[name=’myName’]”) selects all <input> elements with name=”myName”)
- Child selectors (e.g. $(“ul > li”) selects all <li> elements that are direct children of a <ul> element)
- Descendant selectors (e.g. $(“div p”) selects all <p> elements that are descendants of a <div> element)
46. What is the difference between the HtmlHelper and UrlHelper classes in ASP.NET MVC?
| HtmlHelper | UrlHelper | |
|---|---|---|
| Purpose | Generates HTML markup for views | Generates URLs for views |
| Namespace | System.Web.Mvc | System.Web.Mvc |
| Usage | Used to generate HTML elements with attributes and validation | Used to generate URLs for action methods, routes, and content |
| Extension Methods | Contains extension methods for HTML element generation | Contains extension methods for URL generation |
| Examples | Html.TextBoxFor(), Html.LabelFor() | Url.Action(), Url.RouteUrl() |
47. What is the use of AJAX in ASP.NET?
- AJAX (Asynchronous JavaScript and XML) is a technique used to create web applications that can update parts of a web page without requiring a full page refresh.
- In ASP.NET, AJAX can be used to make asynchronous requests to the server, allowing for more responsive and interactive user interfaces.
- AJAX can be used to fetch data from a server, submit form data, and perform other operations without requiring a full page refresh.
48. What is the difference between synchronous and asynchronous AJAX calls?
- Synchronous AJAX calls block the user interface until the request is completed, while asynchronous AJAX calls allow the user interface to continue functioning while the request is being processed.
- Synchronous AJAX calls are simpler to implement, but can make the user interface unresponsive and are generally discouraged in modern web development.
- Asynchronous AJAX calls are more complex to implement, but provide a better user experience by allowing the interface to remain responsive.
49. What is the use of Web Services in ASP.NET?
- Web Services are used to expose functionality over the internet, allowing applications to interact with each other over standard protocols such as HTTP and XML.
- In ASP.NET, Web Services can be used to provide data and functionality to other applications, regardless of the programming language or platform used by the client application.
- Web Services can be used to build distributed applications, integrate with third-party services, and provide data to mobile applications and other client-side technologies.
50. What is the difference between SOAP and RESTful Web Services?
- SOAP (Simple Object Access Protocol) is a protocol for exchanging structured information between applications over standard protocols such as HTTP and XML.
- REST (Representational State Transfer) is a style of web architecture that uses standard HTTP methods (GET, POST, PUT, DELETE) to interact with resources identified by URLs.
- SOAP is more rigid and requires a formal contract between the client and server, while RESTful services are more flexible and can be more easily consumed by a variety of clients.
- RESTful services are generally simpler to implement, while SOAP services provide more functionality out of the box.
51. What is the use of SignalR in ASP.NET?
- SignalR is a library for building real-time web applications using technologies such as WebSockets, Server-Sent Events, and long-polling.
- In ASP.NET, SignalR can be used to build applications that require real-time communication between the server and client, such as chat applications, multiplayer games, and real-time data visualization.
- SignalR allows for bi-directional communication between the server and client, allowing the server to push updates to the client without the client having to request them.
52. What is the difference between SignalR and WebSocket?
- WebSockets are a protocol for bi-directional, real-time communication between the client and server over a single TCP connection.
- SignalR is a library built on top of WebSockets that provides additional functionality, such as automatic fallback to other transport protocols (e.g. long-polling) for clients that do not support WebSockets.
- SignalR also provides a higher-level API for building real-time applications, while WebSockets are a lower-level protocol that require more manual implementation.
53. What is the syntax for writing a switch statement in ASP.NET?
The syntax is:
| switch(variable){ case value: code block; break; default: code block; } |
54. What is the difference between Routing and URL Rewriting in ASP.NET?
- Routing is a mechanism for mapping URLs to server-side code, allowing for more flexible and dynamic URLs.
- URL Rewriting is a mechanism for modifying the URLs that are sent to the server, allowing for cleaner and more user-friendly URLs.
- Routing maps a URL to a server-side resource (e.g. a controller action), while URL Rewriting modifies the URL that is sent to the server without changing the underlying resource that is being accessed.
55. What is the use of HTML Helpers in ASP.NET?
- HTML Helpers are a set of methods provided by ASP.NET MVC that simplify the creation of HTML elements and forms.
- HTML Helpers can be used to generate HTML code that is correctly formatted and compliant with web standards, reducing the risk of errors and improving maintainability.
- HTML Helpers can also be used to improve code organization and reduce the amount of boilerplate code required for common tasks such as form handling and validation.
56. What is the difference between GET and POST requests in ASP.NET?
| Aspect | GET | POST |
|---|---|---|
| Request limit | Limited by the maximum length of the URL | Unlimited, as data is sent in the request body |
| Security | Less secure as data is sent in the URL and can be intercepted | More secure as data is sent in the request body and encrypted |
| Caching | Can be cached by the browser and server | Cannot be cached by the browser, but can be cached by server |
| Idempotent | Idempotent, meaning that multiple requests with the same URL have the same effect and produce the same result | Not idempotent, meaning that multiple requests with the same data may have different effects and produce different results |
| Usage | Typically used for fetching data | Typically used for submitting data |
57. What is the difference between Html.Partial and Html.RenderPartial?
- Both Html.Partial and Html.RenderPartial are used to render a partial view in an ASP.NET MVC application.
- The main difference between them is that Html.RenderPartial writes the partial view directly to the response stream, while Html.Partial returns the rendered partial view as a string that can be used elsewhere in the code.
- In terms of performance, Html.RenderPartial is generally faster because it writes directly to the response stream without creating an intermediate string.
58. What is the use of ViewData and ViewBag in ASP.NET?
- ViewData and ViewBag are used to pass data from a controller to a view in an ASP.NET MVC application.
- ViewData is a dictionary-like object that is used to pass data as key-value pairs. It requires casting the values in the view.
- ViewBag is a dynamic object that is used to pass data as properties. It does not require casting in the view.
59. What is the difference between TempData and Session in ASP.NET?
- TempData and Session are used to store data between requests in an ASP.NET MVC application.
- The main difference between them is that TempData is used to store data for a single request and is cleared after that request is processed, while Session is used to store data for the entire user session.
- TempData is useful for scenarios where data needs to be persisted for the next request, such as after a redirect.
60. What is the use of Action Results in ASP.NET?
- Action Results are used to return a result from an action method in an ASP.NET MVC application.
- Action Results can return various types of results such as ViewResult, PartialViewResult, JsonResult, ContentResult, and FileResult, among others.
61. What is the difference between ActionResult and ViewResult in ASP.NET?
- ActionResult is the base class for all action results in an ASP.NET MVC application.
- ViewResult is a type of ActionResult that returns a view as a result of an action method.
- ViewResult is typically used when returning a view with a model from an action method.
62. How do you define a new constructor in ASP.NET?
The syntax is:
| [access modifier] ClassName(parameters){ code block } |
63. What is the use of the Razor View Engine in ASP.NET?
- The Razor View Engine is a view engine used in ASP.NET MVC to generate HTML markup.
- It provides a simple syntax for writing views using Razor markup, which is a combination of HTML and C# or VB.NET code.
64. What is the difference between HTML and XML?
- HTML is a markup language used for creating web pages that are displayed in a web browser.
- XML is a markup language used for storing and transporting data.
- HTML has predefined tags and attributes for styling and displaying content, while XML allows for the creation of custom tags and attributes to represent data.
65. What is the difference between GET and POST requests in ASP.NET?
| Aspect | GET | POST |
|---|---|---|
| Request method | Requests data from a specified resource | Submits an entity to a specified resource |
| Request payload | Sends data in the URL query string | Sends data in the request body |
| Data length | Limited by the URL length restrictions | Not limited by the URL length restrictions |
| Security | Less secure as data is exposed in the URL | More secure as data is hidden in the request body |
| Caching | Can be cached by the browser and server | Cannot be cached by the browser, but can be cached by server |
| Idempotence | Generally considered safe and idempotent | Not considered safe or idempotent |
| Usage | Used for data retrieval, like fetching a web page or image | Used for submitting data, like submitting a form or login |
66. What is the use of XML in ASP.NET?
- XML is commonly used in ASP.NET for various purposes such as configuration files, data exchange between applications, and web services.
- In ASP.NET, XML can be used to store application settings and other configuration information in a web.config file.
67. What is the difference between XPath and XQuery?
- XPath is a language used to navigate and select elements in an XML document.
- XQuery is a more powerful language that can be used to query and transform XML data.
- While XPath is limited to selecting elements and attributes, XQuery can perform complex queries and manipulate the XML data.
68. What is the use of XSLT in ASP.NET?
- XSLT (Extensible Stylesheet Language Transformations) is used to transform XML data into another format such as HTML, plain text, or another XML document.
- In ASP.NET, XSLT can be used to transform XML data before rendering it in a web page.
69. Difference between web.config and app.config in ASP.NET:
- web.config is used in web applications, while app.config is used in desktop applications.
- web.config contains configuration settings specific to the web application, while app.config contains settings specific to the desktop application.
70. Use of machine.config in ASP.NET:
- machine.config is a global configuration file that applies to all applications running on the machine.
- It contains settings such as security policies, database connection strings, and runtime settings.
71. Use of NuGet in ASP.NET:
- NuGet is a package manager for .NET that allows you to easily install and manage third-party libraries and dependencies.
- It simplifies the process of adding external components to your project and ensures that all required dependencies are automatically installed.
72. Difference between .NET Framework and .NET Core:
- .NET Framework is a Windows-only framework that includes a large set of libraries and APIs.
- .NET Core is a cross-platform, open-source framework that includes a smaller set of libraries and APIs and can run on Windows, macOS, and Linux.
73. Use of the .NET Standard:
- The .NET Standard is a specification that defines a set of APIs that all .NET implementations should support.
- It allows developers to create libraries that can be used across different platforms and implementations, including .NET Framework, .NET Core, and Xamarin.
74. Difference between a class and an interface in C#:
- A class is a blueprint for creating objects, while an interface defines a set of methods and properties that a class must implement.
- A class can inherit from another class, but can implement multiple interfaces.
75. Use of the abstract keyword in C#:
- The abstract keyword is used to define a class or method that cannot be instantiated or implemented directly.
- It serves as a template for other classes or methods to inherit from and implement.
76. Difference between a value type and a reference type in C#:
- A value type stores its value directly in memory, while a reference type stores a reference to its value in memory.
- Value types include primitive types such as int and bool, while reference types include classes, interfaces, and arrays.
77. Use of the async and await keywords in C#:
- The async and await keywords are used to create asynchronous methods in C#.
- They allow the method to continue executing while waiting for a long-running operation to complete, improving the responsiveness of the application.
78. Use of the using statement in C#:
- The using statement is used to automatically dispose of objects that implement the IDisposable interface.
- It ensures that resources such as file handles and database connections are released as soon as they are no longer needed, improving performance and avoiding memory leaks.
79. What is the difference between a static class and a non-static class in C#?
- A static class can’t be instantiated, while a non-static class can be.
- A static class can only contain static members, while a non-static class can contain both static and instance members.
- Static members in a static class are shared across all instances, while instance members in a non-static class belong to individual instances.
80. What is the use of the sealed keyword in C#?
The sealed keyword is used to prevent inheritance of a class or to prevent overriding of a method in a derived class.
81. What is the difference between a delegate and an event in C#?
- A delegate is a type that represents a method signature, while an event is a mechanism for notifying clients when an action occurs.
- An event is based on a delegate and provides a level of abstraction and encapsulation that a delegate does not.
82. What is the use of the out keyword in C#?
The out keyword is used to specify that a method parameter is being passed by reference for output purposes only, meaning the method can modify the value of the parameter.
83. What is the difference between the out and ref keywords in C#?
Both out and ref keywords are used for passing arguments by reference, but ref requires the variable to be initialized before being passed as a parameter, while out does not.
84. What is the use of the override keyword in C#?
The override keyword is used to indicate that a method in a derived class is intended to override a method in the base class.
85. What is the difference between the virtual and abstract keywords in C#?
- A virtual method provides a default implementation in the base class that can be overridden in derived classes, while an abstract method has no implementation in the base class and must be implemented in any derived classes.
- A virtual method can be called directly, while an abstract method can only be called through a derived class implementation.
86. What is the use of LINQ in C#?
LINQ (Language Integrated Query) provides a set of extensions to the C# language that allows for querying and manipulating data from various sources, such as databases and collections.
87. What is the difference between IEnumerable and IQueryable in C#?
- IEnumerable is used for querying data in memory, while IQueryable is used for querying data in external data sources, such as databases.
- IQueryable allows for more efficient querying, as it can translate queries to the native query language of the data source.
88. What is the use of the var keyword in C#?
- The var keyword is used to implicitly declare a variable and infer its type from the context in which it is used. It can be useful for reducing code verbosity and improving readability.
89. What is the difference between a lambda expression and a delegate in C#?
- A delegate is a type that represents a method signature, allowing for methods to be passed as arguments to other methods or stored as variables.
- A lambda expression is a shorthand syntax for defining a delegate or an expression tree, making it easier to write inline functions.
90. What is the use of the Func and Action delegates in C#?
- The Func delegate is a built-in delegate type that takes up to 16 input parameters and returns a value of a specified type.
- The Action delegate is a built-in delegate type that takes up to 16 input parameters and does not return a value.
- These delegates can be used to simplify code and reduce boilerplate by allowing functions to be passed as arguments or stored as variables.
91. What is the difference between a constructor and a method in C#?
- A constructor is a special method that is called when an object of a class is created, allowing for initialization of instance variables and other setup tasks.
- A method is a regular function that can be called on an object of a class or on the class itself.
- Constructors have no return type and are named after the class, while methods can have any return type and can be named anything.
92. What is the use of the StringBuilder class in C#?
- The StringBuilder class is used for efficient manipulation of strings that require frequent modifications.
- Strings in C# are immutable, meaning that any modification results in a new string being created in memory. The StringBuilder class allows for modifications to be made in-place, reducing memory usage and improving performance.
93. What is the difference between a try-catch block and a try-finally block in C#?
- A try-catch block is used to handle exceptions that occur within a block of code, allowing for graceful recovery and error reporting.
- A try-finally block is used to ensure that certain cleanup or finalization tasks are always performed, regardless of whether an exception occurs or not.
94. What is the use of the IEnumerable interface in C#?
- The IEnumerable interface is used to define a sequence of elements that can be enumerated using a foreach loop or other iteration methods.
- Implementing the IEnumerable interface allows for custom collections or data structures to be used in generic algorithms and LINQ queries.
95. What is the difference between a private and protected access modifier in C#?
- The private access modifier restricts access to members of a class to only that class, preventing other classes from accessing or modifying them.
- The protected access modifier allows members of a class to be accessed by derived classes, but not by other classes.
96. What is the use of the finally block in C#?
- The finally block is used to ensure that certain cleanup or finalization tasks are always performed, regardless of whether an exception occurs or not.
- This can be used to release resources, close files or connections, or perform other important cleanup tasks.
97. What is the difference between a static constructor and a non-static constructor in C#?
- A static constructor is called when the class is first loaded into memory, and is used to initialize static fields or perform other static setup tasks.
- A non-static constructor is called when an object of the class is created, and is used to initialize instance variables or perform other instance-specific setup tasks.
98. What is the use of the extension method in C#?
- An extension method is a method that is used to extend the functionality of an existing class or interface without modifying its source code.
- Extension methods are defined as static methods in a static class, and can be called on instances of the extended class as if they were instance methods.
99. What is the usage of IIS?
- IIS enables your computer to function as a Web server and facilitates the development and deployment of Web applications on the server.
- The request and response cycle on the Web server is managed by IIS.
- SMTP and FrontPage server extensions are also available as services with IIS.
- SMTP allows for sending emails, while FrontPage server extensions allow for the dynamic features of IIS, such as the form handler.
100. What is a multilingual website?
- A multilingual website is one that provides content in multiple languages.
- It includes multiple copies of content and resources, such as date and time, in different languages.
- Multilingual websites are useful for reaching a wider audience and providing content in a user’s preferred language.
- They require additional planning and resources to create and maintain, including translation and localization services.
The Top 100 ASP.NET Interview Questions and Answers provide a comprehensive resource for job seekers and employers to assess technical knowledge and problem-solving skills. To enhance your knowledge, do follow us at freshersnow.com.