Node.js, JavaScript, API - Interview Questions and Answers

John Edward Cooper Berg

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Published by John Edward Cooper Berg

Copyright 2019-2020 John Edward Cooper Berg

Cover design and title page: John Edward Cooper Berg

Edit: John Edward Cooper Berg

Composition: John Edward Cooper Berg

Publisher: John Edward Cooper Berg

Contact to author: john.e.cooper.berg@gmail.com

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Contents

NODE.JS - BASICS

NPM

JAVASCRIPT - BASICS

TESTING

API

SOURCE CODE

PATTERNS

MISCELLANEOUS

Acknowledgement

My Udemy course

NODE.JS - BASICS

Q. What is Node.JS?

Node.js is an open-source, cross-platform, JavaScript run-time environment that executes JavaScript code outside of a browser. Node.js lets developers use JavaScript to write command line tools and for server-side scripting—running scripts server-side to produce dynamic web page content before the page is sent to the user's web browser. Consequently, Node.js represents a JavaScript everywhere paradigm, unifying web application development around a single programming language, rather than different languages for server- and client-side scripts.

Q. What are Node.JS advantages?

- is fast

- almost never blocks

- offers a unified programming language and data type

- everything is asynchronous

Q. What is Event Driven Programming followed in Node.js?

Event-Driven Programming makes use of the following concepts:

An Event Handler is a callback function that will be called when an event is triggered.

A Main Loop listens for event triggers and calls the associated event handler for that event.

Node.js natively provides a module called EventEmitter that allows us to get started incorporating Event-Driven Programming in our project.

Q. Describe please Node.js architecture

Node.js brings event-driven programming to web servers, enabling development of fast web servers in JavaScript. Developers can create scalable servers without using threading, by using a simplified model of event-driven programming that uses callbacks to signal the completion of a task. Node.js connects the ease of a scripting language (JavaScript) with the power of Unix network programming.

Node.js was built on the Google V8 JavaScript engine since it was