NestJS Introduction 3

Question 1

Which HTTP adapter does NestJS use by default under the hood?

Accepted Answer

Express

Answer

NestJS uses Express as its default HTTP platform, though it can be swapped for Fastify for higher performance.

Question 2

What does the 'exports' array in @Module() define?

Accepted Answer

Providers that other modules can import and use

Answer

The 'exports' array specifies which providers from the current module should be available to other modules that import it.

Question 3

How do you switch NestJS from Express to Fastify?

Accepted Answer

Pass FastifyAdapter to NestFactory.create()

Answer

You import FastifyAdapter from @nestjs/platform-fastify and pass it as the second argument to NestFactory.create().

Question 4

What is the role of the @Injectable() decorator in NestJS?

Accepted Answer

Marks a class as a provider manageable by the DI system

Answer

@Injectable() tells NestJS that this class can be injected as a dependency and managed by the IoC container.

Question 5

Which NestJS concept is analogous to Angular's concept of modules?

Accepted Answer

Modules decorated with @Module()

Answer

NestJS was heavily inspired by Angular, and both use @Module() to organize code into cohesive feature blocks.

NestJS Practice Test