NestJs Questions

Abhishek Singh

Score: 🔥 23

Beginner

Took 3 minutes

Programming Framework

NestJs

80%

Questions Attempted

10 / 10

Correct Answers

Incorrect Answers

Points Earned

🔥 8

Question 1

What is a key advantage of using NestJS over plain Express.js for building Node.js applications?

NestJS is faster for handling HTTP requests
NestJS enforces a strict project structure and uses TypeScript for better code organization
NestJS is more lightweight and has fewer dependencies
NestJS directly interacts with the database, eliminating the need for ORMs

Explanation:

NestJS promotes code reusability and maintainability through its modular structure and by leveraging TypeScript. While it's built upon Express.js, it adds a significant layer of organization and type safety.

Question 2

After installing the NestJS CLI, what command is used to initiate a new NestJS project?

nest new project-name
nestjs create-app my-app
npm init nestjs-app
create-react-app my-nestjs-project

Explanation:

The nest new command followed by your desired project name is the standard way to start a new NestJS project using the CLI.

Question 3

What is the purpose of the @Res() decorator in NestJS?

To define a new route
To access route parameters
To directly interact with the response object
To handle asynchronous operations

Explanation:

The @Res() decorator provides access to the underlying Express response object, allowing for manual manipulation of the response, such as setting headers or sending custom status codes.

Question 4

What is the advantage of using built-in HTTP exception filters in NestJS?

They provide a streamlined way to handle common HTTP errors with predefined responses.
They allow you to bypass the need for exception handling altogether.
They are only applicable for database-related exceptions.
They are primarily used for handling authentication and authorization errors.

Explanation:

NestJS's built-in filters simplify error handling by providing ready-to-use responses for standard HTTP errors, reducing the need for repetitive code.

Question 5

What is the default scope of a provider in NestJS?

Singleton
Transient
Request-scoped
Module-scoped

Explanation:

In NestJS, providers are singletons by default. This means that a single instance of the provider is created and shared across the entire application.

Question 6

What is the role of Providers in NestJS?

To render UI elements.
To define the application's entry point.
To handle data persistence.
To provide dependencies that can be injected into other components like controllers or services.

Explanation:

Providers are fundamental to NestJS's dependency injection system. They can be classes annotated with @Injectable(), and their instances can be injected into constructors of other components, promoting code reusability and testability.

Question 7

What is the purpose of the useFactory property in a FactoryProvider?

To specify the class that the factory function should return.
To define a function that creates and returns an instance of the provider.
To provide a static value for the provider.
To configure the lifecycle hooks of the provider.

Explanation:

The useFactory property in a FactoryProvider is used to define a factory function. This function is responsible for creating and returning an instance of the provider. It can be asynchronous and can inject dependencies.

Question 8

Which programming language forms the foundation of NestJS?

Python
Java
JavaScript/TypeScript
Ruby

Explanation:

NestJS is built on top of Node.js, and it primarily uses either JavaScript or TypeScript (a superset of JavaScript) for building applications.

Question 9

When using an Interceptor to modify the response, what is the best way to ensure type safety?

Type casting within the Interceptor.
Using generics with the NestInterceptor interface.
Disabling type checks within the Interceptor.
Type checking is not necessary within Interceptors.

Explanation:

For type safety, define generics with the NestInterceptor interface, specifying the expected request and response types, allowing TypeScript to perform type checking.

Question 10

What is the primary purpose of exception handling in a NestJS backend application?

To gracefully handle and respond to unexpected errors during request processing.
To enforce strict data typing in controller methods.
To handle database migrations and schema changes.
To define middleware functions for request-response cycles.

Explanation:

Exception handling is crucial for preventing application crashes and providing meaningful error responses to clients when unexpected situations arise during request handling.