ASP.NET Core is a popular open-source web framework developed by Microsoft. It is widely used for building modern, scalable, and high-performance web applications. If you are preparing for an ASP.NET Core interview, this detailed guide will help you understand key concepts, answer important questions, and confidently approach technical discussions.
Basic ASP.NET Core Interview Questions
1. What is ASP.NET Core?
Answer:
ASP.NET Core is a cross-platform, high-performance, open-source framework for building modern web applications. It is a re-architected version of ASP.NET that allows developers to run applications on Windows, Linux, and macOS.
2. What are the key features of ASP.NET Core?
Answer:
- Cross-platform support (Windows, macOS, Linux)
- High performance and lightweight
- Dependency Injection (DI) support
- Middleware-based request processing pipeline
- Built-in support for cloud-based applications
- Unified MVC and Web API frameworks
- Open-source and actively developed by Microsoft and the community
3. What is Middleware in ASP.NET Core?
Answer:
Middleware is a component in ASP.NET Core that processes requests and responses. It is used to handle authentication, logging, exception handling, and request processing before passing it to the next component.
Example:
public void Configure(IApplicationBuilder app)
{
app.Use(async (context, next) =>
{
await context.Response.WriteAsync("Hello from Middleware 1");
await next();
});
app.Use(async (context, next) =>
{
await context.Response.WriteAsync("Hello from Middleware 2");
await next();
});
}4. How is Dependency Injection implemented in ASP.NET Core?
Answer:
Dependency Injection (DI) is a core concept in ASP.NET Core. It allows for loosely coupled code by injecting dependencies at runtime.
Example:
public interface IGreetingService
{
string Greet();
}
public class GreetingService : IGreetingService
{
public string Greet() => "Hello, ASP.NET Core!";
}
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<IGreetingService, GreetingService>();
}Intermediate ASP.NET Core Interview Questions
5. Explain the Startup.cs file in ASP.NET Core.
Answer:
The Startup.cs file is the entry point of an ASP.NET Core application. It contains two main methods:
ConfigureServices(): Registers services with the dependency injection container.Configure(): Defines the middleware pipeline for request handling.
6. What is the difference between AddTransient, AddScoped, and AddSingleton?
Answer:
AddTransient: Creates a new instance every time it is requested.AddScoped: Creates a single instance per request.AddSingleton: Creates a single instance for the lifetime of the application.
Advanced ASP.NET Core Interview Questions
7. How does ASP.NET Core handle authentication and authorization?
Answer:
ASP.NET Core supports authentication and authorization using JWT, OAuth, and Identity framework.
Example:
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(options =>
{
options.TokenValidationParameters = new TokenValidationParameters
{
ValidateIssuer = true,
ValidateAudience = true,
ValidateLifetime = true,
ValidateIssuerSigningKey = true
};
});8. What is Kestrel in ASP.NET Core?
Answer:
Kestrel is the default web server in ASP.NET Core. It is lightweight, high-performance, and supports asynchronous processing.
9. What is Entity Framework Core, and how does it work in ASP.NET Core?
Answer:
Entity Framework Core (EF Core) is an ORM (Object-Relational Mapper) used to interact with databases in ASP.NET Core applications.
Example:
public class ApplicationDbContext : DbContext
{
public DbSet<User> Users { get; set; }
}10. How does ASP.NET Core support Cyber Security Services?
Answer:
ASP.NET Core provides built-in security features such as:
- Data protection APIs
- Cross-Site Request Forgery (CSRF) protection
- CORS (Cross-Origin Resource Sharing)
- HTTPS enforcement
- Identity-based authentication
These features help businesses, including Cyber Security Services, to implement secure and resilient web applications.
Conclusion
ASP.NET Core is a robust framework for web development, and having a good understanding of its concepts can help you succeed in interviews. The questions covered in this article range from basic to advanced levels, with practical examples to aid your understanding. If you are a company offering Cyber Security Services, integrating ASP.NET Core in your solutions ensures high-performance, secure applications.
