1. Explain the concept of garbage collection in .NET and its significance in application development.

Answer:

Garbage collection in .NET is an automated memory management process that automatically reclaims memory occupied by objects that are no longer in use, preventing memory leaks. The Common Language Runtime (CLR) uses a garbage collector to identify and reclaim memory occupied by objects that are no longer reachable. This process enhances application performance, reduces manual memory management errors, and ensures efficient memory utilization.

2. Differentiate between ASP.NET Web Forms and ASP.NET MVC. Provide scenarios where each is preferable.

Answer:

• ASP.NET Web Forms:
  • Based on the event-driven programming model.
  • Abstracts the stateless nature of the web, providing a familiar desktop application paradigm.
  • Suitable for rapid development and simpler page-based applications.
• ASP.NET MVC:
  • Follows the Model-View-Controller architectural pattern.
  • Provides greater control over HTML and JavaScript, facilitating cleaner and more maintainable code.
  • Suitable for large-scale applications with complex user interfaces, where testability and separation of concerns are crucial.

Scenario:

• Use Web Forms for projects with tight deadlines and simple user interfaces.
• Choose MVC for projects requiring extensive client-side interactions, testability, and a more organized code structure.

3. How does Dependency Injection (DI) enhance software design in .NET applications? Provide an example.

Answer:

Dependency Injection promotes loose coupling by allowing the injection of dependencies into a class rather than creating them within the class. This enhances code maintainability, testability, and flexibility.

Example:

4. Discuss the advantages of using asynchronous programming in .NET applications. Provide a real-world scenario.

Answer:

Asynchronous programming in .NET enables non-blocking execution, improving application responsiveness. It is beneficial for operations such as I/O-bound tasks or network requests, where waiting for a response could lead to performance degradation.

Scenario:

Consider a web application where a user uploads a large file. Using asynchronous programming allows the server to continue handling other requests while waiting for the file upload to complete. This ensures that the application remains responsive, providing a better user experience.

5. How does ASP.NET Core differ from previous versions of ASP.NET, and why is it considered a cross-platform framework?

Answer:

ASP.NET Core is a cross-platform, high-performance framework that can run on Windows, Linux, and macOS. It differs from previous versions of ASP.NET in the following ways:

• Cross-platform Support: ASP.NET Core is designed to be platform-agnostic, enabling developers to build and run applications on different operating systems.
• Modular Architecture: It follows a modular and lightweight architecture, allowing developers to include only the components needed for their application, reducing the overall footprint.
• Open-source: ASP.NET Core is open-source, fostering community collaboration and rapid innovation.
• Built-in Dependency Injection: ASP.NET Core includes a built-in dependency injection system, simplifying the management of application dependencies.

6. Explain the importance of the Entity Framework in database interactions and provide an example of its usage.

Answer:

Entity Framework (EF) is an Object-Relational Mapping (ORM) framework in .NET that simplifies database interactions by allowing developers to work with database entities as .NET objects.

7. What is the significance of the ASP.NET Core middleware and how does it contribute to the request processing pipeline?

Answer:

ASP.NET Core middleware components are responsible for processing requests and responses in the request pipeline. They can perform tasks such as authentication, logging, compression, and more.

Significance:

Middleware components can be added to the pipeline in a specific order, allowing developers to customize the request-handling process. This modular approach provides flexibility and reusability in building web applications.

8. Discuss the role of the .NET Core CLI (Command-Line Interface) in modern application development.

Answer:

The .NET Core CLI is a command-line interface that provides a set of commands for creating, building, running, and publishing .NET applications. Its role in modern application development includes:

• Cross-platform Development: The CLI enables developers to build and run applications on different platforms using a consistent set of commands.
• Project Management: Developers can create, restore, build, and publish projects without relying on integrated development environments (IDEs).
• Tooling Integration: The CLI integrates with various development tools, making it suitable for continuous integration and deployment scenarios.

9. Explain the purpose of the ASP.NET Core Razor Pages and how they differ from MVC.

Answer:

ASP.NET Core Razor Pages provide a lightweight alternative to MVC, focusing on building page-centric, data-driven web applications. Unlike MVC, where controllers and views are separate, Razor Pages combine the view and controller into a single file.

• Convention Over Configuration: Razor Pages follow a convention-based approach, reducing the need for explicit configuration.
• Simplicity: Razor Pages are designed for simplicity, making it easier to build small to medium-sized applications with less ceremony.
• Tight Coupling: In Razor Pages, the code for handling a page’s request is colocated with the page itself, leading to tighter coupling compared to the separation in MVC.

10. Describe the role of the Global Assembly Cache (GAC) in .NET and situations where using it is appropriate.

Answer:

The Global Assembly Cache (GAC) is a shared location in the .NET framework where strongly named assemblies can be stored and shared by multiple applications. It is primarily used for storing shared assemblies that need to be accessed by multiple applications on the same machine.

Situations for GAC Usage:

• Shared Libraries: When multiple applications need to use the same version of a library, placing it in the GAC avoids redundancy.
• Strongly Named Assemblies: Assemblies in the GAC must be strongly named, ensuring versioning and preventing conflicts between different versions of the same assembly.

Using the GAC is appropriate when centralized management and versioning of shared assemblies are essential for the stability of multiple applications.

11. Discuss the benefits of using Attribute-based Routing in ASP.NET MVC and provide an example.

Answer:

Attribute-based Routing in ASP.NET MVC allows developers to define routes using attributes, providing a more declarative and readable way to configure routing. This approach enhances code organization and makes it easier to understand the relationship between routes and actions.

12. Explain the concept of View Components in ASP.NET Core MVC and their role in building modular and reusable UI components.

Answer:

View Components in ASP.NET Core MVC are similar to partial views but offer more flexibility and reusability. They encapsulate a piece of UI logic and rendering, making it easy to create modular components that can be reused across different parts of a web application.

Role in Modularity:

View Components are useful for breaking down complex user interfaces into smaller, manageable components. They promote code reuse and maintainability by encapsulating specific UI functionality.

13. Describe the importance of NuGet in .NET development and how it simplifies library management.

Answer:

NuGet is a package manager for .NET that simplifies the process of adding, updating, and removing libraries in a .NET project. It plays a crucial role in managing dependencies, enabling developers to easily integrate third-party libraries into their projects.

• Dependency Management: NuGet automates the process of downloading and updating dependencies, reducing manual effort.
• Versioning: It provides version control, allowing developers to specify the version of a library needed for their project.
• Centralized Repository: NuGet hosts a centralized repository of packages, making it convenient to discover and integrate libraries.

14. How does .NET Core support microservices architecture, and what are the advantages of building applications using microservices?

Answer:

.NET Core supports microservices architecture by providing a lightweight and modular framework that allows developers to build and deploy microservices independently.

Advantages of microservices include:

• Scalability: Microservices can be independently scaled based on the demand for specific services.
• Flexibility: Each microservice can be developed, deployed, and updated independently, providing agility and flexibility.
• Technology Diversity: Different microservices within an application can use different technologies, allowing developers to choose the best tool for each task.

15. Discuss the role of the Health Checks feature in ASP.NET Core and its significance in monitoring application health.

Answer:

Health Checks in ASP.NET Core provide a way to monitor the health of an application by exposing a health status endpoint. This endpoint can be used for various purposes, including load balancers, container orchestrators, and application monitoring tools.

• Proactive Monitoring: Health Checks enable proactive monitoring of application components, helping detect and address issues before they impact users.
• Integration with Orchestration Tools: Container orchestrators, such as Kubernetes, can use health checks to determine the state of application instances and make informed decisions about scaling or restarting.

16. Explain the concept of Blazor in .NET and its role in building interactive web applications.

Answer:

Blazor is a framework in .NET that allows developers to build interactive web applications using C# and .NET instead of JavaScript. It enables the development of Single Page Applications (SPAs) with both client and server-side capabilities.

• C# on the Client: Blazor allows developers to write client-side code in C#, which is executed in the browser using WebAssembly.
• Code Sharing: Blazor enables code sharing between client and server components, promoting reusability.
• Component-Based Architecture: Blazor applications are built using a component-based architecture, making it easier to manage and organize UI elements.

17. Discuss the role of the .NET Core Identity framework in handling user authentication and authorization in web applications.

Answer:

The .NET Core Identity framework provides a set of APIs for handling user authentication, authorization, and managing user information. It simplifies common identity-related tasks in web applications, such as user registration, login, and role-based authorization.

• User Authentication: Identity facilitates user authentication through various mechanisms, including username/password, social logins, and multi-factor authentication.
• Role-Based Authorization: It allows developers to define roles and restrict access to certain parts of the application based on a user’s role.
• User Management: Identity provides APIs for managing user accounts, including password recovery and account lockout policies.

18. How does .NET support cross-platform mobile app development, and what role does Xamarin play in this ecosystem?

Answer:

.NET supports cross-platform mobile app development through Xamarin, a framework that allows developers to build native mobile apps using C# and .NET. Xamarin enables code sharing between iOS and Android platforms, reducing development effort and ensuring consistency.

• Shared Codebase: Xamarin allows developers to share a significant portion of their codebase between iOS and Android applications.
• Native Performance: Xamarin applications deliver native performance as they are compiled to native binaries.
• Integration with Visual Studio: Xamarin integrates seamlessly with Visual Studio, providing a familiar development environment for .NET developers.

19. Explain the concept of Asynchronous Messaging in distributed systems and the role of technologies like Azure Service Bus or RabbitMQ in implementing it.

Answer:

Asynchronous Messaging in distributed systems involves decoupling components by allowing them to communicate through messages. Azure Service Bus and RabbitMQ are message brokers that facilitate asynchronous communication.

• Decoupling Components: Asynchronous messaging decouples sender and receiver components, allowing them to operate independently.
• Scalability: Message queues enable horizontal scalability, as components can process messages independently and in parallel.
• Reliability: Message brokers provide features like message persistence, delivery guarantees, and fault tolerance, enhancing system reliability.

20. Discuss the role of .NET Core in building cloud-native applications and its compatibility with cloud platforms like Azure.

Answer:

.NET Core is well-suited for building cloud-native applications due to its lightweight, modular, and cross-platform nature. It is compatible with cloud platforms like Azure, providing seamless integration and support for cloud-native features.

• Containerization: .NET Core applications can be containerized using Docker, facilitating easy deployment and scaling in cloud environments.
• Microservices Architecture: .NET Core supports the development of microservices, enabling the creation of scalable and independently deployable components.
• Azure Integration: .NET Core applications can leverage Azure services, such as Azure App Service, Azure Functions, and Azure SQL Database, for building robust and scalable cloud-native solutions.