NestJs Questions

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Score: 🔥 117

Beginner

Took 13 minutes

Programming Framework

NestJs

70%

Questions Attempted

10 / 10

Correct Answers

Incorrect Answers

Points Earned

🔥 7

Question 1

What is the role of the 'main.ts' file in a NestJS project?

Defines the application's database schema and models
Contains unit tests for the application's logic
Creates and configures the NestJS application instance
Stores environment variables and configuration settings

Explanation:

The main.ts file is the entry point of your NestJS application. It bootstraps the NestJS application, often setting up the listening port and other core configurations.

Question 2

What is the purpose of dependency injection in NestJS?

To handle errors gracefully.
To manage database connections.
To provide a mechanism for creating and injecting dependencies into classes.
To define the application's routing logic.

Explanation:

Dependency injection is a design pattern where dependencies are 'injected' into a class rather than being directly instantiated within the class. This promotes modularity, testability, and reusability.

Question 3

Which HTTP method does the @Post() decorator handle?

GET
POST
PUT
DELETE

Explanation:

The @Post() decorator is used to designate a controller method as a handler for incoming HTTP POST requests, typically used for creating resources.

Question 4

Which design pattern heavily influences the architecture of NestJS?

Singleton
Factory
Observer
Dependency Injection

Explanation:

Dependency Injection is a core principle in NestJS. It allows for loosely coupled modules and promotes better testability and flexibility within your application.

Question 5

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 6

Can a Controller access a Service's methods in NestJS?

No, Controllers and Services are completely isolated.
Yes, by injecting the Service into the Controller's constructor.
Yes, by using static methods of the Service.
Only if the Controller and Service are defined in the same module.

Explanation:

In NestJS, a Controller can access a Service's methods by injecting an instance of the Service through the Controller's constructor. This is facilitated by NestJS's Dependency Injection mechanism.

Question 7

What decorator is used for handling HTTP requests meant for updating resources?

@Post()
@Put()
@Delete()
@Patch()

Explanation:

The @Put() decorator marks a controller method for handling HTTP PUT requests, typically used for complete updates of existing resources.

Question 8

What is the role of CallHandler in the intercept method of an Interceptor?

It provides access to the dependency injection container.
It handles errors thrown within the Interceptor.
It represents the next Interceptor in the chain or the route handler itself.
It provides utility methods for transforming the request object.

Explanation:

The CallHandler in the intercept method allows you to call the next Interceptor in line or, if it's the last Interceptor, to trigger the execution of the route handler.

Question 9

What is the purpose of the return statement in a NestJS controller method?

To define the route path
To specify middleware for the route
To send the response to the client
To handle errors within the route

Explanation:

The value returned from a NestJS controller method forms the response sent back to the client. This can be a simple object, a string, or more complex data.

Question 10

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.