Nirvana Solutions Interview Questions and Answers

Interfaces define a contract for classes to implement. They are used to achieve abstraction and polymorphism.

• Interfaces allow for loose coupling between classes

• They provide a way to achieve multiple inheritance in Java

• Real-life example: USB port - different devices can be plugged into the same port because they all adhere to the USB interface

• Another example: Remote control - different TV brands can be controlled by the same remote because they all implement the same interface

I have worked on various technologies including Java, Python, and JavaScript. I have experience with versions ranging from Java 8 to Java 14.

• Worked on Java 8, 11, and 14 for developing enterprise applications

• Developed web applications using Python 3 and Flask framework

• Used JavaScript and React for building user interfaces

• Experience with version control systems like Git and SVN

Authorization is the process of granting access to specific resources, while authentication is the process of verifying the identity of a user.

• Authentication confirms the identity of a user through credentials such as username and password, biometrics, or tokens.

• Authorization determines what actions a user can perform on a system or resource based on their authenticated identity.

• Examples of authentication include logging into a website or using a fingerprint scanner to unlock...read more

Dependency injection is a design pattern that allows objects to receive dependencies from an external source rather than creating them themselves.

• Dependency injection helps to decouple the code and makes it more testable and maintainable.

• It allows for easier swapping of dependencies without changing the code.

• There are three types of dependency injection: constructor injection, setter injection, and interface injection.

• Example: Instead of creating a database connection object ...read more

JWT token is a JSON web token used for authentication and authorization purposes.

• JWT token is a compact, URL-safe means of representing claims to be transferred between two parties.

• It is digitally signed and can be verified by the recipient to ensure that the claims contained in the token are genuine.

• It consists of three parts: header, payload, and signature.

• JWT token is commonly used in web applications for user authentication and authorization.

• Some popular libraries for imp...read more

Middleware in Dotnet Core is a component that sits between the client and the server to handle requests and responses.

• Middleware is a pipeline of components that can process requests and responses in Dotnet Core applications.

• Middleware can be used for logging, authentication, authorization, error handling, and more.

• Middleware is added to the application pipeline using the 'UseMiddleware' method in the 'Configure' method of the 'Startup' class.

• Each middleware component in the ...read more