Infosys Dot Net Core Developer Interview Questions and Answers

Global exception handling in .NET Core allows centralized management of errors in web applications.

• Use middleware to catch exceptions globally. Example: app.UseMiddleware<ExceptionHandlingMiddleware>();

• Implement custom exception filters for specific scenarios. Example: [ServiceFilter(typeof(CustomExceptionFilter))]

• Return standardized error responses. Example: new ObjectResult(new { error = ex.Message }) { StatusC...read more

Securing a web API involves implementing authentication, authorization, and encryption.

• Implement authentication to verify the identity of the client accessing the API

• Implement authorization to control what actions the client can perform

• Use HTTPS to encrypt the communication between the client and the API

• Implement rate limiting to prevent abuse and protect against denial-of-service attacks

• Apply input validation and outp...read more

Improving web API performance involves optimizing code, caching, using asynchronous programming, and scaling infrastructure.

• Optimize code by reducing unnecessary database queries, using efficient algorithms, and minimizing network calls.

• Implement caching to store frequently accessed data and reduce the load on the server.

• Use asynchronous programming to handle multiple requests concurrently and improve responsiveness.

• Sc...read more

OOPs concepts include encapsulation, inheritance, polymorphism, and abstraction, essential for structured programming.

• Encapsulation: Bundling data and methods that operate on the data within one unit, e.g., a class.

• Inheritance: Mechanism where one class inherits properties and methods from another, e.g., a 'Dog' class inheriting from an 'Animal' class.

• Polymorphism: Ability to present the same interface for different da...read more

Delegates are function pointers used to encapsulate methods, while generics are used to create reusable code for different data types.

• Delegates are used to create callbacks and event handlers.

• Generics allow the creation of classes, methods, and interfaces that can work with different data types.

• Delegates can be used to define and invoke methods dynamically at runtime.

• Generics provide type safety and eliminate the need ...read more

Generics can be used in projects to create reusable code that can work with different types.

• Generics can be used in data structures like lists, dictionaries, and queues to store and retrieve different types of data.

• Generics can be used in algorithms and functions to work with different types of inputs and outputs.

• Generics can be used in database operations to handle different types of data.

• Generics can be used in user ...read more

Delegates are used to create references to methods, allowing methods to be passed as parameters or stored as variables.

• Delegates provide a way to achieve callback functionality in C#.

• Delegates can be used to implement event handling.

• Delegates enable loose coupling and separation of concerns.

• Delegates can be used to create and invoke anonymous methods.

• Delegates can be used to implement the observer pattern.

Join query using Entity Framework

• Use the LINQ query syntax to perform joins in Entity Framework

• Use the 'join' keyword to specify the join condition

• Use 'into' keyword to create a group join

• Use 'on' keyword to specify the join condition

• Use 'equals' keyword to define the equality condition

Dependency injection is a design pattern that allows objects to be loosely coupled by providing their dependencies externally.

• Dependency injection is a way to achieve inversion of control in software development.

• It helps in creating loosely coupled and modular code.

• In dependency injection, the dependencies of a class are provided externally rather than being created within the class itself.

• This allows for easier testin...read more

To handle large number of records in a web API, you can use pagination, streaming, or compression techniques.

• Implement pagination to retrieve records in smaller chunks

• Use streaming to process and return records in real-time

• Apply compression techniques like GZIP to reduce the size of the response

• Consider caching strategies to improve performance

The project structure in Dot Net Core typically consists of folders for source code, configuration files, and dependencies.

• The source code is usually organized into folders based on the application's modules or layers, such as Controllers, Models, and Views.

• Configuration files like appsettings.json store application settings and connection strings.

• Dependencies are managed using a package manager like NuGet, and their v...read more

Entity Framework provides a higher level of abstraction, simplifies database operations, improves productivity, and reduces code complexity.

• Entity Framework abstracts away the underlying database, allowing developers to work with a higher level of abstraction.

• It simplifies database operations by providing an object-oriented approach to data access.

• Entity Framework improves productivity by reducing the amount of code ne...read more

Program.cs is the entry point of a .NET Core application, while Startup.cs configures services and middleware.

• Program.cs contains the Main method which is the entry point of the application

• Startup.cs configures services and middleware for the application

• In Program.cs, you can configure the host and call the Startup class

• Startup.cs typically includes ConfigureServices and Configure methods

The main difference between .NET and .NET Core is that .NET Core is a cross-platform, open-source framework while .NET is a Windows-only framework.

• NET Core is cross-platform and can run on Windows, macOS, and Linux, while .NET is limited to Windows.

• .NET Core is open-source and community-driven, while .NET is developed and maintained by Microsoft.

• .NET Core is modular and lightweight, allowing developers to include only ...read more

Factory pattern. Creates objects without exposing the instantiation logic to the client.

• Defines an interface for creating objects, but lets subclasses decide which classes to instantiate.

• Client only knows the abstract type, not the concrete type.

• Used when a class cannot anticipate the type of objects it must create.

• Examples: Abstract Factory, Singleton, Builder, Prototype.

Startup class is a class in ASP.NET Core that is used to configure services and middleware for the application.

• It is responsible for configuring the application's request pipeline.

• It is used to register services that the application will use.

• It is where middleware components are added to the pipeline.

• It can be used to configure the application's logging and exception handling.

• It is typically found in the Startup.cs fil...read more

Dependency injection is a design pattern used to inject dependencies into a class or method.

• Create an interface for the dependency

• Create a class that implements the interface

• Register the class with the dependency injection container

• Inject the dependency into the class or method

• Use the dependency in the class or method

Scoped, transient and singleton are three different lifetimes for services in .NET Core.

• Scoped services are created once per request and are disposed at the end of the request.

• Transient services are created each time they are requested.

• Singleton services are created once and are reused throughout the lifetime of the application.

• Use scoped services for components that are request-specific, transient services for lightwe...read more

WAP to find the prime number

• Loop through numbers and check if divisible by any number less than it

• Exclude 1 and the number itself

• 2 is the only even prime number

A program to reverse the letters of a given string.

• Create an empty string to store the reversed string

• Iterate through the original string from the end to the beginning

• Append each character to the empty string

• Return the reversed string

I am a Dot Net Core Developer with expertise in location-based services and technical skills in various programming languages.

• Location: I am currently based in New York City, which is a major hub for technology and innovation.

• Technical Skills: I have extensive experience in developing web applications using Dot Net Core, C#, ASP.NET, and SQL Server.

• I am proficient in front-end technologies like HTML, CSS, and JavaScrip...read more

I want to join Infosys because of its reputation as a leading global IT services company.

• Infosys has a strong presence in the IT industry and is known for its expertise in delivering innovative solutions.

• Joining Infosys would provide me with opportunities to work on challenging projects and enhance my skills.

• Infosys has a collaborative work culture that encourages learning and growth.

• The company offers competitive comp...read more