Node.js Interview Questions and Answers

CORS is a Node.js package used for providing a Connect/Express middleware.

Consistent style can help your team members modify projects easily without the need to learn a new style for every project. Some of the useful tools are Standard and ESLint.

They have globally installed packages or dependencies that are stored in the /npm directory. These dependencies can be used in Command Line Interface (CLI) of any node.js. However, they cannot be imported using require () command in Node application directly. In order to install a Node project globally, you need to use -g flag.

Local mode is the package installation in the node-modules directory in the same folder where Node application is stored. By default, the Node Package Manager (NPM) installs dependencies in the local mode. Most locally deployed packages are also accessible via require(). In order to install a Node project locally, you need to follow the syntax.

EventEmitter class lies in the events module and is accessibly through the following syntax:

//import events module
var events = require('events');
//create an eventEmitter object
var eventEmitter = new events.EventEmitter();

In case an EventEmitter instance is facing error, it emits 'error' event. When a new listener is added, the 'newListener' event gets fired and when a listener gets removed, 'removeListener' event gets fired.

V8 Engine is Google's open-source javascript and written in C++. It is used inside Google Chrome. It was first designed to increase the performance of JavaScript execution inside web browsers.

Multiple reasons are listed below:

• In the comparison of HTTP servers, it provides the non-blocking of the input/output.
• Node reduces the total number of servers that serve an equal amount of requests.
• This uses the single process for managing the multiple requests.
• By using the single-thread process, the computing speed will get increased and it also saves a lot of space.

Async and await are used to make the code easier to write and read. Also, the agenda behind rolling out this feature is to deal with the promises and functions chaining in the Node. Where the functions do not need to be chained just one after another, simply call the await function that returns the promise. On the other hand, the function async should be declared before returning a promise by awaiting a function.

ExpressJS is one prebuilt framework of NodeJS that can assist the users in building server-side web apps faster plus smarter. Simplicity, flexibility, minimalism, scalability are a few of its many characteristics and as it is built inside NodeJS itself, Express inherited its execution as well.

ExpressJS streamlined coding in Node JS to a great extent and provided programmers some extra features to increase their coding of the server-side. There is no doubt in the fact that it is the most famous frameworks of all in today’s time.

Representational State Transfer or REST is a standard web-based architecture. REST makes use of the HTTP Protocol. It twirls around resources where each and every element is one resource and the resource is obtained by the common interface with the help of standard HTTP methods. This was first proposed by a man named Roy Fielding in the year 2000. The REST Server solely renders entrance to resources as well as REST client accesses plus modifies these resources with the help of the HTTP protocol. And here each and every resource is recognized by URIs or by global IDs. It uses numerous representations to present the resource such as text, or JSON, or XML, etc.