1. What is .NET Core?
.NET Core is an open-source, cross-platform framework developed by Microsoft. It allows developers to build applications that can run on Windows, macOS, and Linux.

2. What are the advantages of using .NET Core?
Some advantages of using .NET Core include:
– Cross-platform compatibility
– High-performance and scalability
– Open-source
– Support for microservices architecture

3. What is the difference between .NET Framework and .NET Core?
.NET Framework is a Windows-only framework, while .NET Core is cross-platform. .NET Core is also modular and lightweight compared to the monolithic .NET Framework.

4. Explain the concept of Middleware in .NET Core.
Middleware in .NET Core is software components that are arranged in a chain to process HTTP requests and responses. Each middleware component can process the request or response and either pass it to the next component or terminate the pipeline.

5. What is the role of the Startup class in .NET Core?
The Startup class is responsible for configuring the services and middleware that are used by the application. It is the entry point for configuring the application’s request pipeline and dependency injection.

6. What is dependency injection in .NET Core?
Dependency injection is a design pattern used to implement loose coupling between classes. It allows classes to depend on abstractions instead of concrete implementations. .NET Core has built-in support for dependency injection.

7. What is the difference between AddSingleton, AddScoped, and AddTransient in dependency injection?
– AddSingleton: A single instance of the service is created and shared across all requests.
– AddScoped: A new instance of the service is created for each HTTP request.
– AddTransient: A new instance of the service is created every time it is requested.

8. What is Entity Framework Core?
Entity Framework Core is an object-relational mapping (ORM) framework provided by .NET Core. It allows developers to work with databases using .NET objects and provides a range of features, including database migrations and query capabilities.

9. What is the difference between EF Core and EF6?
EF Core is a lightweight and cross-platform version of Entity Framework, while EF6 is the legacy version that only runs on the full .NET Framework. EF Core has a different API surface and is designed to be more modular and performant.

10. Explain the concept of Razor Pages in ASP.NET Core.
Razor Pages is a new feature in ASP.NET Core that allows developers to build web pages with minimal code-behind files. It follows the MVVM (Model-View-ViewModel) pattern and provides a simple and intuitive way to build web applications.

11. What is the use of appsettings.json file in ASP.NET Core?
The appsettings.json file is used to store configuration settings for an ASP.NET Core application. It allows developers to define settings such as database connection strings, API keys, and logging settings.

12. How can you enable authentication and authorization in ASP.NET Core?
Authentication and authorization can be enabled in ASP.NET Core by using middleware components and configuring authentication schemes. The authentication middleware verifies the identity of the user, while the authorization middleware checks if the user is authorized to perform a certain action.

13. What is the use of the IActionResult interface in MVC?
The IActionResult interface in MVC represents the result of an action method. It allows the controller to return different types of results, such as a view, JSON data, or a redirect.

14. How can you implement validation in ASP.NET Core?
Validation in ASP.NET Core can be implemented using data annotations, custom validation attributes, or by creating custom validation logic in the controller. The framework automatically validates the incoming data based on the defined rules.

15. What is the role of the IHostingEnvironment interface?
The IHostingEnvironment interface provides information about the hosting environment of the application, such as the current environment name and the content root path. It is used for configuring the application based on the current environment.

16. How can you log messages in ASP.NET Core?
ASP.NET Core provides a logging API that can be used to log messages in the application. It supports different logging providers, such as console, file, and database. Logging can be configured in the appsettings.json file.

17. How can you handle errors in ASP.NET Core?
Errors in ASP.NET Core can be handled using middleware components, exception filters, or by customizing the built-in error pages. The framework provides a centralized way to handle exceptions and return appropriate responses.

18. What is the use of the IActionResult interface in MVC?
The IActionResult interface in MVC represents the result of an action method. It allows the controller to return different types of results, such as a view, JSON data, or a redirect.

19. How can you implement caching in ASP.NET Core?
Caching in ASP.NET Core can be implemented using in-memory caching, distributed caching, or response caching. The framework provides built-in support for different caching providers, such as MemoryCache and RedisCache.

20. How can you deploy an ASP.NET Core application?
ASP.NET Core applications can be deployed using different methods, such as self-contained deployment, framework-dependent deployment, or deploying to a Docker container. The deployment method depends on the target platform and the requirements of the application.

1. What is .NET Core?
.NET Core is an open-source, cross-platform framework for building modern applications. It is a successor to the .NET Framework and provides enhanced performance, modularity, and scalability.

2. What are the main advantages of .NET Core?
The main advantages of .NET Core include:

– Cross-platform compatibility
– High performance
– Modularity and easy deployment
– Open-source nature
– Ability to run on different cloud platforms

3. What are the key components of .NET Core?
The key components of .NET Core are:

– The .NET Runtime: It provides the necessary runtime and libraries to execute applications.
– The .NET Core Framework: It offers a set of APIs and libraries for application development.
– The .NET Core SDK: It includes compilers, tools, and libraries for developing and building applications.

4. Explain the concept of Middleware in .NET Core.
Middleware in .NET Core is a component that sits between the webserver and the application’s request handling pipeline. It allows developers to add modular processing components to handle requests and responses. Examples of middleware include authentication, logging, and error handling.

5. What are the advantages of using Entity Framework Core?
Entity Framework Core is a lightweight, extensible ORM framework for .NET Core applications. Its advantages include:

– Rapid development by providing database abstraction.
– Support for multiple databases.
– Automatic generation of database schema.
– Easy migration and cross-platform compatibility.

6. What is the purpose of Dependency Injection in .NET Core?
Dependency Injection (DI) is a design pattern used in .NET Core to achieve loose coupling between components. It allows objects to obtain their dependencies from external sources, rather than creating them internally. DI enhances testability, maintainability, and modularity of applications.

7. Explain the concept of Razor Pages in .NET Core.
Razor Pages is a feature in .NET Core that enables developers to build simple web pages with minimal setup and coding. It follows the Model-View-Controller (MVC) pattern and simplifies the development of UI-focused applications.

8. What are the different types of storage options available in .NET Core?
The different storage options available in .NET Core are:

– File system storage
– SQL databases (e.g., Microsoft SQL Server)
– NoSQL databases (e.g., MongoDB)
– In-memory storage (e.g., Redis cache)

9. Explain the concept of gRPC in .NET Core.
gRPC is a high-performance, open-source framework for building distributed applications. It uses Protocol Buffers for efficient data serialization and provides cross-platform support for microservices communication.

10. How can you secure .NET Core applications?
.NET Core provides various options for securing applications, such as:

– Authentication and authorization middleware
– Token-based authentication using JWT (JSON Web Tokens)
– Role-based access control
– HTTPS/SSL encryption

11. What is the role of Kestrel in .NET Core?
Kestrel is a cross-platform, built-in web server in .NET Core. It is fully asynchronous, allowing it to handle a large number of concurrent connections efficiently. Kestrel serves as the default web server for .NET Core applications.

12. How can you handle logging in .NET Core?
.NET Core provides a built-in logging framework called Microsoft.Extensions.Logging. Developers can configure various log providers, such as Console, Debug, EventLog, or a custom provider, to handle logging in their applications.

13. What is the purpose of Health Checks in .NET Core?
Health Checks in .NET Core provide a way to monitor the health of an application in real-time. They can be used to check the status of dependencies, such as databases or external services. Health Checks help ensure the availability and reliability of applications.

14. Explain the concept of Entity Framework Migrations.
Entity Framework Migrations offer a way to evolve the database schema over time. It enables developers to track and apply incremental changes to the database schema using code-first or database-first approaches. Migrations simplify the process of database versioning and deployment.

15. What is the purpose of SignalR in .NET Core?
SignalR is a real-time communication library in .NET Core that allows bi-directional communication between clients and servers. It enables applications to push real-time updates to connected clients, making it suitable for applications like chat apps or live dashboards.

16. How can you deploy .NET Core applications?
.NET Core applications can be deployed using various methods, including:

– Self-contained deployments: Applications and the .NET Core runtime are bundled together for easy distribution and execution.
– Docker containers: Applications can be containerized and deployed using container orchestration platforms like Kubernetes.
– Azure Cloud: Deploying to Azure App Service or Azure Kubernetes Service is a popular option.

17. How can you improve the performance of .NET Core applications?
To improve the performance of .NET Core applications, you can consider the following techniques:

– Implementing caching mechanisms (e.g., using Redis cache)
– Optimizing database queries (e.g., through indexing)
– Using relevant profiling and benchmarking tools for performance analysis
– Employing asynchronous programming patterns where applicable

18. What is the purpose of Entity Framework Core InMemory Provider?
The InMemory Provider in Entity Framework Core allows developers to simulate a database in memory for testing or development purposes. It provides an in-memory database that can be used for rapid testing without the need for an external database.

19. Explain the concept of Logging Middleware in .NET Core.
Logging Middleware in .NET Core sits in the request pipeline and logs information about requests and responses. It helps developers debug and monitor their applications by capturing relevant details and writing them to designated log providers.

20. What is the difference between .NET Core and .NET Framework?
The main differences between .NET Core and .NET Framework include:

– Cross-platform compatibility: .NET Core is cross-platform, while .NET Framework is Windows-only.
– Deployment method: .NET Core can be deployed as self-contained or via Docker containers, whereas .NET Framework is typically deployed as binaries on a Windows machine.
– Performance: .NET Core offers better performance and scalability compared to .NET Framework.
– Portability: .NET Core allows easy migration between different platforms, while .NET Framework is tightly coupled to Windows.