Node.js Express.js & REST APIs

Question 1

What is middleware in Express.js?

Accepted Answer

Functions that have access to the request, response, and next function in the application's request-response cycle

Answer

Software installed between the client browser and the server hardware

Answer

A database layer between the application and storage

Answer

CSS libraries that sit between HTML and JavaScript

Question 2

What HTTP method should be used to update an existing resource in a REST API?

Accepted Answer

PUT or PATCH

Answer

GET

Answer

POST

Answer

DELETE

Question 3

What is the purpose of 'app.use()' in Express.js?

Accepted Answer

To mount middleware functions that will execute for every request matching the specified path

Answer

To declare the application will use a specific database

Answer

To import utility functions from npm packages

Answer

To define the application's user interface layout

Question 4

What is CORS and how is it handled in Express?

Accepted Answer

Cross-Origin Resource Sharing — a security mechanism configured via the 'cors' middleware package

Answer

A database connection pooling library

Answer

A caching strategy for reducing server load

Answer

A CSS rendering optimization for server-side rendering

Question 5

What status code should a REST API return when a resource is successfully created?

Accepted Answer

201 Created

Answer

200 OK

Answer

204 No Content

Answer

301 Moved Permanently

Question 6

What is the purpose of route parameters in Express?

Accepted Answer

To capture dynamic values from the URL path for use in request handlers

Answer

To set query parameters in the response

Answer

To define the maximum number of routes allowed

Answer

To configure routing table priorities