C#
Dotnet Interview Questions and Answers
1. What is .NET?
.NET is a software framework developed by Microsoft that primarily runs on Microsoft Windows. It provides a large class library and supports several programming languages.
2. Describe Garbage collection in .NET?
Garbage collection is the automatic process of reclaiming memory occupied by objects that are no longer in use. It helps manage memory efficiently and prevents memory leaks.
3. What is the difference between Value types and Reference types in .NET?
Value types directly contain their data, while reference types store a reference to their data. Value types are stored on the stack, while reference types are stored on the heap.
4. What are the Advantages of .NET?
- Simplified deployment
- Language independence
- Security
- Interoperability
- Base class library
- Consistent programming model
5. Explain the Common Language Runtime (CLR)?
CLR is the virtual machine component of the .NET framework. It manages the execution of .NET programs, providing features such as memory management, exception handling, and garbage collection.
6. Explain the difference between Managed code and Unmanaged code?
Managed code is code that runs under the control of the CLR and benefits from features such as automatic memory management and exception handling. Unmanaged code does not run under the control of the CLR and must manage its own memory and resources.
7. What is the purpose of the .NET framework Class Library?
The .NET framework Class Library provides a comprehensive collection of reusable types that simplify and expedite the development of applications. It includes classes for tasks such as file I/O, networking, and database access.
8. What is the Global Assembly Cache (GAC)?
The GAC is a machine-wide cache used by .NET to store assemblies specifically designated to be shared by multiple applications on the same machine. It allows assemblies to be shared among multiple applications without copying the assembly into the application's directory.
9. How does Inheritance work in .NET?
Inheritance in .NET allows a class (derived class) to inherit members from another class (base class). The derived class can then extend or modify the behavior of the base class by adding new members or overriding existing ones.
10. What is an Interface in .NET?
An interface in .NET defines a contract that classes can implement. It specifies a set of methods and properties that a class must provide, but it does not provide any implementation details. Classes that implement an interface must provide implementations for all of its members.
11. Explain the concept of Boxing and Unboxing in .NET?
Boxing is the process of converting a value type to a reference type, while unboxing is the process of converting a reference type back to a value type. These operations involve copying the value of a value type into an object on the heap or extracting the value from the object, respectively.
12. What is the role of the Common Type System (CTS) in .NET?
The Common Type System (CTS) defines the types that can be used in the .NET framework and ensures that types written in different .NET languages can interoperate seamlessly.
13. What are Delegates in .NET?
Delegates in .NET are type-safe function pointers that allow methods to be passed as parameters to other methods. They provide a way to invoke methods dynamically and are commonly used in event handling and callback mechanisms.
14. What is the purpose of the garbage collector in .NET?
The garbage collector in .NET is responsible for automatically reclaiming memory occupied by objects that are no longer in use. It helps manage memory efficiently, prevents memory leaks, and improves application performance.
15. Describe the difference between Events and Delegates in .NET?
Delegates provide a way to invoke methods dynamically, while events provide a mechanism for communication between objects. Events are based on delegates and allow objects to subscribe to and receive notifications when certain actions occur.
16. How does Exception handling work in .NET?
Exception handling in .NET allows developers to handle runtime errors and unexpected conditions gracefully. It involves the use of try, catch, and finally blocks to detect and handle exceptions, ensuring that programs can recover from errors and continue executing.
17. Explain the purpose of the Reflection API in .NET?
The Reflection API in .NET allows developers to inspect and manipulate metadata, types, and assemblies at runtime. It provides a way to dynamically load assemblies, discover types, and invoke members without prior knowledge of their structure.
18. What are Attributes in .NET?
Attributes in .NET provide a way to add metadata to types and members. They allow developers to annotate code with additional information that can be queried at runtime using reflection.
19. What is the role of the Assembly class in .NET?
The Assembly class in .NET represents an assembly, which is a reusable, versionable, and self-describing building block of a .NET application. It provides methods and properties for working with assemblies, such as loading, inspecting, and executing them.
20. Explain the difference between Binary serialization and XML serialization in .NET?
Binary serialization in .NET stores object data in binary format, resulting in smaller file sizes and faster serialization and deserialization. XML serialization, on the other hand, stores object data in XML format, which is human-readable and can be easily processed by other systems.
21. What is Serialization in .NET?
Serialization in .NET is the process of converting objects into a stream of bytes for storage or transmission. It allows objects to be saved to disk, sent over a network, or persisted in a database in a platform-independent format.
22. Describe the difference between The stack and The heap in .NET?
The stack and the heap are two regions of memory used for storing data in .NET. The stack is used for storing value types and method call information, while the heap is used for storing reference types and objects whose lifetime is not determined by their scope.
23. What is the purpose of the System.IO namespace in .NET?
The System.IO namespace in .NET provides classes for performing input and output operations, such as reading from and writing to files, streams, and directories. It allows developers to work with files and data on the filesystem.
24. How does Threading work in .NET?
Threading in .NET allows multiple tasks to run concurrently within the same application. It involves creating and managing threads, synchronizing access to shared resources, and coordinating the execution of tasks to improve performance and responsiveness.
25. What is the Task Parallel Library (TPL) in .NET?
The Task Parallel Library (TPL) in .NET provides a high-level abstraction for parallel programming. It allows developers to create and manage tasks asynchronously, leverage multicore processors, and improve the performance of parallelizable algorithms.
26. Describe the purpose of the LINQ language integrated query in .NET.
LINQ in .NET allows developers to query and manipulate data using a unified syntax integrated into the programming language. It provides a consistent and expressive way to work with data from different sources such as databases, collections, and XML.
27. What are Anonymous types in .NET?
Anonymous types in .NET allow developers to create objects without explicitly defining a class. They are typically used in LINQ queries to represent projections of data or intermediate results.
28. Explain the concept of a lambda expression in .NET?
A lambda expression in .NET is an anonymous function that can be used to create delegates or expression tree types. It provides a concise syntax for defining inline functions and is commonly used in LINQ queries and event handling.
29. What is the purpose of the Entity Framework in .NET?
The Entity Framework in .NET is an object-relational mapping (ORM) framework that simplifies data access by enabling developers to work with relational data as domain-specific objects. It abstracts the underlying database schema and provides a higher-level programming model for data access.
30. What is the purpose of the ASP.NET framework in .NET?
The ASP.NET framework in .NET is used for building dynamic web applications and services. It provides a robust, scalable, and extensible platform for creating web pages, web services, and web applications using various technologies such as Web Forms, MVC, and Web API.
31. Explain the difference between ASP.NET Web Forms and ASP.NET MVC?
ASP.NET Web Forms is a traditional event-driven web development framework that abstracts the underlying HTTP protocol and allows developers to create web applications using a stateful programming model. ASP.NET MVC, on the other hand, is a lightweight and highly testable web framework based on the Model-View-Controller architectural pattern, which promotes separation of concerns and testability.
32. Describe the difference between IEnumerable and IQueryable in .NET?
IEnumerable in .NET represents a collection of objects that can be enumerated sequentially, typically in memory. IQueryable, on the other hand, represents a queryable data source that can be composed and executed asynchronously, typically against a Database.
33. What is the purpose of the ASP.NET Core framework in .NET?
ASP.NET Core is a cross-platform, high-performance, and open-source framework for building modern web applications and services. It provides a unified programming model for developing web applications and APIs that can run on Windows, macOS, and Linux.
34. Describe the difference between Authentication and Authorization in ASP.NET?
Authentication in ASP.NET is the process of verifying the identity of users, typically through credentials such as usernames and passwords. Authorization, on the other hand, is the process of determining what actions users are allowed to perform after they have been authenticated, based on their roles or permissions.
35. What is the purpose of the ASP.NET Web API framework in .NET?
The ASP.NET Web API framework in .NET is used for building HTTP services that can be consumed by various clients, including web browsers, mobile devices, and desktop applications. It provides a simple and flexible way to expose data and functionality over the web using standard HTTP protocols.
36. Explain the concept of Routing in ASP.NET MVC?
Routing in ASP.NET MVC is the process of mapping incoming HTTP requests to controller actions based on URL patterns. It allows developers to define custom routes that determine how URLs are parsed and how requests are routed to the appropriate controller and action method.
37. What is the purpose of the Entity Framework Core in .NET?
Entity Framework Core is a lightweight and extensible version of the Entity Framework ORM framework designed for use with ASP.NET Core applications. It provides a powerful and flexible way to work with relational databases by allowing developers to map domain objects to database tables and query data using LINQ.
38. Describe the difference between Synchronous and Asynchronous programming in .NET?
Synchronous programming in .NET involves executing tasks sequentially, where each operation must complete before the next one begins. Asynchronous programming, on the other hand, allows tasks to execute concurrently, enabling non-blocking execution and improved scalability and responsiveness.
39. What is the purpose of the NuGet package manager in .NET?
The NuGet package manager in .NET is used for managing dependencies and packages in .NET projects. It allows developers to easily find, install, update, and remove packages from their projects, streamlining the process of integrating third-party libraries and components.
40. Explain the concept of Middleware in ASP.NET Core?
Middleware in ASP.NET Core is software components that are added to the request processing pipeline to handle requests and responses. Each middleware component in the pipeline can perform specific tasks, such as logging, authentication, or error handling, and can modify the request or response before passing it on to the next component.
