Asp.Net MVC Interview Questions & Answers

Basics of ASP.NET MVC:

1. What is ASP.NET MVC?

   • Answer: ASP.NET MVC is a web development framework by Microsoft that follows the Model-View-Controller (MVC) architectural pattern. It provides a structured way to build dynamic web applications.

2. Explain the MVC architectural pattern.

   • Answer: MVC separates an application into three components: Model (data and business logic), View (presentation layer), and Controller (handles user input and updates the Model and View).

3. What are the advantages of using ASP.NET MVC over Web Forms?

   • Answer: Advantages include better control over HTML, support for clean and testable code, separation of concerns, and improved support for modern web development patterns.

4. What is the role of the Model in ASP.NET MVC?

   • Answer: The Model represents the application's data and business logic. It is responsible for retrieving and storing data, as well as defining rules for data validation and manipulation.

5. Explain the purpose of Razor view engine in ASP.NET MVC.

   • Answer: Razor is a view engine used in ASP.NET MVC to embed server-side code within HTML markup. It simplifies the syntax for writing dynamic content in views.

Controllers in ASP.NET MVC:

6. What is a Controller in ASP.NET MVC?

   • Answer: A Controller is a class that handles user input, processes requests from the View, and updates the Model or selects a View to be rendered.

7. Explain the ActionResult class in ASP.NET MVC.

   • Answer: ActionResult is a base class for classes that define the result of an action method. It represents the data that will be sent to the client in response to a request.

8. What is the purpose of the TempData in ASP.NET MVC?

   • Answer: TempData is used to pass data from the current request to the next request. It is particularly useful in scenarios where data needs to be preserved across redirects.

9. How can you handle errors in ASP.NET MVC applications?

   • Answer: Errors in ASP.NET MVC can be handled using custom error pages, the HandleError attribute, and implementing the Application_Error event in the Global.asax file.

10. Explain the concept of Action Filters in ASP.NET MVC.

    • Answer: Action Filters are attributes that can be applied to controller actions to perform pre-processing or post-processing logic. They provide a way to inject behavior into the request processing pipeline.

Views and Razor Syntax:

11. What is a View in ASP.NET MVC?

    • Answer: A View is responsible for presenting the user interface. It contains the HTML markup and may include embedded server-side code to display dynamic content.

12. Explain the purpose of the @model directive in Razor views.

    • Answer: The @model directive is used in Razor views to define the type of the model that the view expects. It provides strong typing for the view and enables IntelliSense support.

13. How do you pass data from a Controller to a View in ASP.NET MVC?

    • Answer: Data is passed from a Controller to a View using the ViewData, ViewBag, and strongly-typed models. The recommended approach is to use strongly-typed models.

Routing in ASP.NET MVC:

14. What is routing in ASP.NET MVC?

    • Answer: Routing is the process of mapping URLs to controller actions. It defines the rules for how URLs should be structured and which controller actions should be invoked.

15. Explain the significance of the Global.asax file in ASP.NET MVC.

    • Answer: The Global.asax file in ASP.NET MVC contains events such as Application_Start and Application_End and is used to configure settings and handle application-level events.

Model Binding and Validation:

16. What is Model Binding in ASP.NET MVC?

    • Answer: Model Binding is the process of mapping data from HTTP requests to action method parameters or model properties. It simplifies the handling of form data and query parameters.

17. Explain the purpose of Data Annotations in ASP.NET MVC.

    • Answer: Data Annotations are attributes applied to model properties to define validation rules, such as required fields, string length, and regular expressions. They help enforce data validation.

Security and Authentication:

18. How can you implement authentication in ASP.NET MVC applications?

    • Answer: Authentication in ASP.NET MVC can be implemented using Forms Authentication, Windows Authentication, or external providers like OAuth and OpenID Connect.

19. Explain Cross-Site Request Forgery (CSRF) and how to prevent it in ASP.NET MVC.

    • Answer: CSRF is an attack where an unauthorized user makes a request on behalf of an authenticated user. Prevention involves using anti-forgery tokens and validating requests.

Testing in ASP.NET MVC:

20. What are the common testing approaches used in ASP.NET MVC applications?
    • Answer: Common testing approaches include unit testing using frameworks like MSTest or NUnit, integration testing, and end-to-end testing using tools like Selenium. Testing controllers and views is essential for maintaining code quality.