ExpressJS Interview Questions and Answers

Question 1

What are theadvantagesof using Express.js with Node.js?

Accepted Answer

Express.js makes Node.js backend development faster by simplifying routing, middleware, request handling, static file serving, and API construction.

Question 2

How do youinstall Express.jsin a Node.js project?

Accepted Answer

To install Express.js, create a Node.js project, initialize `package.json`, and run `npm install express`.

Question 3

How tocreate an HTTP Severusing Express.js?

Accepted Answer

An HTTP server in Express is created by initializing an Express app, defining routes, and then calling `app.listen()` on a port.

Question 4

How do youcreateandstart Express.js application?

Accepted Answer

Create the app with `express()`, define at least one route, and start it using `app.listen()`.

Question 5

What is Middlewarein Express.js and whento use them?

Accepted Answer

Middleware in Express.js is a function that runs during the request-response cycle and can inspect, modify, or terminate the request before passing control onward.

Question 6

How do youimplementmiddlewarein Express.js?

Accepted Answer

Middleware is implemented by writing a function with `req`, `res`, and `next`, then registering it with `app.use()` or attaching it to selected routes or routers.

Question 7

What is the purpose of theapp.use()function in Express.js?

Accepted Answer

`app.use()` registers middleware on the application and is commonly used for global processing, parsing, security, logging, and mounting routers.

Question 8

What is the purpose of thenext parameterin Express.js?

Accepted Answer

The `next` parameter passes control to the next middleware or route handler in the chain.

Express.js Interview Questions and Answers

Express - Basics