ASP.NET CORE Top 500 Interview Questions and Answers

Discover ASP.NET Core, a free, open source, high-performance framework for modern cloud-based apps, redesigned as a lean, modular successor with cross-platform and dependency injection capabilities.

ASP.NET core shifts from web forms and MVC 4.8 to a cross-platform, high-performance framework with built-in dependency injection, modular architecture, and flexible hosting options (IIS or self-hosted).

Install the dotnet sdk and choose an ide (Visual Studio or Visual Studio Code). Create a new mvc or api project and run with dotnet run or F5.

Discover the purpose of Program.cs in ASP.NET Core, from host configuration and dependency injection to middleware and logging, and how it evolved from 3.1 to 6.0.

Dotnet core is a modern open source framework by Microsoft for contemporary apps, while mono is a cross-platform .NET implementation overseen by Xamarin for Android, iOS, Windows, and Mac OS.

Differentiate the runtime from the sdk: the runtime executes dotnet core apps, handling memory, type safety, exceptions, and garbage collection, while the sdk provides tools like compilers and libraries.

Define .NET Standard as a formal specification of .NET APIs all platforms must implement. Show how it enables cross-platform code sharing by providing a common API set for .NET applications.

Dotnet enables cross-platform development with a common runtime, and dotnet standard APIs, to build, debug, and deploy apps on Windows, macOS, and Linux.

Learn how the csproj file serves as a central configuration hub for ASP.NET Core apps, defining target frameworks, dependencies, package references, and publishing settings.

Explore EF Core, an open source, cross‑platform ORM that maps model classes to relational databases. Add Microsoft.EntityFrameworkCore, use DbContext, and leverage Linq, change tracking, and migrations with multiple providers.

Configure a database connection in asp.net core with ef core by defining db context, db set, and a connection string in appsettings.json, then register it in program.cs and apply migrations.

Understand development, staging, and production environments in ASP.NET Core, and how environment-specific settings and appsettings.json files control debugging, testing, and deployment behavior.

Discover Kestrel server as the default web server in ASP.NET Core templates, its cross-platform design, lightweight footprint, HTTP/2 support, native SSL termination, and customizable behavior via C# code.

Explore model binding in ASP.NET Core MVC, which automatically maps data from HTTP requests to action method parameters via form values, query strings, route data, headers, cookies, and body.

Show how form values bind to a model in ASP.NET Core MVC, contrasting GET and POST submissions and mapping username and email fields to a user update model.

Demonstrate binding through the query string by showing how category and price are passed as key-value pairs in the URL. Show how this enables model binding in ASP.NET Core MVC.

Learn how route data binds URL segments to action parameters using conventional routing in ASP.NET Core MVC, and how the map controller route passes id parameters from the URL.

Explain data transfer objects in ASP.NET Core MVC, detailing how view back, view data, and temp data pass data from controller to views with different lifetimes.

Master create, read, update, and delete operations with EF Core using a DbContext in an mvc controller, including scaffolding and razor views for index and forms.

Understand how ASP.NET Core session stores data on the server, persisting across requests and enhancing security over cookies. Configure via program.cs with add session, idle timeout, and http-only cookies.

Learn how the repository pattern abstracts data access in ASP.NET Core with a three-layer architecture, using a dedicated repository per entity to improve separation of concerns, testability, and maintainability.

The CLR, or Common Language Runtime, is the .NET execution engine that turns assembly code into native machine code while enabling language interoperability, memory management, security, and exception handling.

Discover how the common type system (CTS) standardizes data types across the .NET framework to enable language interoperability, ensuring that types in VB, C#, and F# are understood across languages.

Describe the common language infrastructure (CLI) as a Microsoft specification that defines executable code and runtime environment, enabling language-neutral cross-language interoperability and platform independence for dotnet applications.

Explain how just-in-time compilation translates IL code to native machine code at runtime within the CLR, enabling dynamic translation of .NET languages like C#.

The dotnet garbage collector automatically allocates and deallocates memory, frees developers from manual management, and reclaims memory while calling finalizers for cleanup when objects are unused.

CoreFX provides the foundational class libraries for dotnet core, offering common APIs for collections, file I/O, networking, serialization, and string manipulation, all in an open-source package on GitHub.

Explain MSIL, or Microsoft intermediate language, also called CIL, as cpu‑independent instruction set into which .NET languages like C# are compiled; IL code sits between high‑level code and native execution.

NuGet packages distribute reusable code libraries and tools for dotnet ecosystem, and NuGet serves as the primary package manager to add third-party libraries, manage versions, and share code across projects.

Understand class libraries: a collection of pre-written, reusable classes that enable code reuse and modularity in dotnet apps, and learn how to create and reference them.

Compare managed and unmanaged code by highlighting CLR execution, garbage collection, type safety, and platform independence for .NET languages, versus native compilation and manual memory management in C and C++.

Explore Entity Framework Core relationships, including one-to-one, one-to-many, and many-to-many, with practical examples using department and employee, country and state, and blog posts, highlighting navigation properties and foreign keys.

Explore how to model many-to-many relationships using a junction table, with student and subject as examples, and configure via fluent API in EF Core with navigation properties.

Demonstrates how to transfer data from a controller to views in ASP.NET Core MVC using strongly typed views, view bag, view data, and temp data.

Clarifies the differences, scope, and lifetimes of view bag, view data, and temp data in ASP.NET Core, highlighting their use within a request versus across redirects and the post-redirect-get pattern.

Discover how paging improves performance and user navigation by loading only portions of data, managing memory, and conserving bandwidth with a practical ASP.NET Core example.

Explore asynchronous programming, enabling concurrent tasks without blocking the main thread, using async and await in C# to perform non-blocking file I/O, network, and database operations.