Node.js Questions Complete Reference Last Updated : 23 Jul, 2025 Comments Improve Suggest changes Like Article Like Report Most people are confused and understand it’s a framework or a programming language. We often use Node.js for building back-end services like APIs like Web App or Mobile App. It’s used in production by large companies such as Paypal, Uber, Netflix, Walmart, and so on. You need to remember that NodeJS is not a framework, and it’s not a programming language. The Complete List of NodeJS Questions are listed below: Installation of Node.js on WindowsInstallation of Node.js on LinuxIntroduction to NodeJSWhy Node.js ?Node.js | NPM (Node Package Manager)How to set node.js console font color ?Difference between process.stdout.write and console.log in NodeJSHow to read command line arguments in Node.js ?Difference Between Django and Node.jsWhat is the difference between –save and –save-dev in Node.js ?Steps to Create and Publish NPM packagesHow to send email with Nodemailer using Gmail account in Node.js ?What is MEVN Stack ?Reading Environment Variables From Node jsHow to make a video call app in node.js ?How to use Radium in React app for inline styling?Difference between Node.JS and JavaScriptHow to install the previous version of node.js and npm ?Essence of Node.jsNodejs | Web Crawling using CheerioModel-View-Controller(MVC) architecture for Node applicationsScaffolding an ExpressJS app from scratchPHP vs. Node.jsNode JS | Password Hashing with Crypto moduleUsing Async Await in Node.jsFull Stack Development with React & Node JS – LiveHow to take input in NodeJS ?How to check if a string is valid MongoDB ObjectId in NodeJS ?How to install an npm package directly from GitHub ?Node.js Chalk ModuleHow to create a directory using NodeJS ?How to set the document value type in MongoDB using NodeJS ?How to add range in the Collection of Mongodb using NodeJS ?How does NPM handle version conflicts ?Default Value in MongoDB using NodeJSTodo List CLI application using Node.jsNodeJs MySQL OR OperatorHow to split each element of an array of strings into different categories using Node.js?Default Value in MongoDB using NodeJSDifference between module.exports and exports in NodeJSHow to install specified directory using npm ?How to connect NodeJS with ReactJS ?How to execute an array of synchronous and asynchronous functions in NodeJS?How to run multiple npm scripts in parallel?Check if NodeJS MySQL Server is Active or notHow to add unique constraint in collection of MongoDB using Node.js?How to use an ES6 import in Node.js?BMI Calculator using Express.jsJWT Authentication with NodeJSHow to copy a file in Node.js?How to convert a file to zip file and download it using NodeJS ?How to define the required Node.js version in package.json?How to determine the user IP address using node.js ?How the single threaded non blocking IO model works in NodeJS ?How to run a node.js application permanently ?How to list npm user-installed packages in Node.js?15 npm Commands that Every Node Developer Should KnowDifference between socket.io and Websockets in Node.jsHow to find the version of an installed npm package in node.js ?How to download a file using Node.js?How to automatically build the package.json file for NodeJS projects?Reading Environment Variables From Node jsDifference between npm install and npm update in Node.jsHow to create and run Node.js project in VS code editor ?Simple Task Manager CLI using Node.jsDifferent types of module used for performing HTTP Request and Response in Node.jsWhy HTTP cookies used and Sending/Receiving HTTP cookies using Node.js ?How to sort collection of MongoDB Database in ascending order using Node.js ?How to sort collection of MongoDB Database in descending order using Node.js ?Count total number of databases present in MongoDB using Node.jsHow to drop all databases present in MongoDb using Node.js ?req.cookies and req.signedCookies in Express.jsHow to get file link from google cloud storage using Node.js ?How to make a video call app in node.js ?Generate a QR code in Node.jsReading QR codes using Node.jsHow to get information of all databases present in MongoDB using Node.js ?How to replace one document in MongoDB using Node.js ?How to count total number of unique documents in MongoDB using Node.js ?How to get information of all collections present in MongoDB database using Node.js ?How to deploy Node.js app on Heroku from GitHub ?How to create different post request using Node.js ?How to read and write Excel file in Node.js ?How to count total number of documents in MongoDB Collection using Node.js ?Difference between npm i and npm ci in Node.jsFeedback form using PugJs, NodeJS, MongoDB, ExpressHow to delete file from the firebase using file url in node.js ?How to find all the values of particular key of MongoDB Database using Node.js ?How to get x and y coordinates of an element in protractor Node.js ?Top 3 Best Packages Of Node.js that you should try being a Node.js DeveloperHow to find all the document keys of MongoDB using Node.js ?Working of Express.js middleware and its benefitsDifference between Node.js and Ruby on RailsHow to parse command line arguments in node.js ?How to Run Multiple Versions of Node.js ?How to drop database of MongoDB using Node.js ?How to get Distinct Documents from MongoDB using Node.js ?How to create new Collection in MongoDB using Node.js ?How to insert single and multiple documents in Mongodb using Node.js ?How to delete single and multiple documents in MongoDB using node.js ?Setting a Default route in Express.jsHow to fetch images from node server ?How to access HTTP Cookie in Node.js ?How to drop collection in MongoDb using Node.js ?How to rename the collection name of MongoDb using Node.js ?How to fetch single and multiple documents from MongoDb using Node.js ?How to create new Mongodb database using Node.js ?How to build a simple Discord bot using Node.js ?How to Design Movie Telegram Bot using Node.js ?How to Scrape a Website Using Puppeteer in Node.js ?Setting up environment variables in Node.js in a platform independent wayHow to connect mongodb Server with Node.js ?How to handle Child Threads in Node.js ?How to install modules without npm in node.js ?NodeJs CRUD Operations Using Mongoose and MongoDB AtlasHow to Convert CSV to JSON file having Comma Separated values in Node.js ?Template Rendering via Marko.js in Node.jsHow to search an element without using any loops in Node.js ?Difference Between EventEmitter and NodeEventTargetHow to sorting an array without using loops in Node.js ?How to validate if input in input field is a valid credit card number using express-validator ?Firebase (sign in with Google) Authentication in Node.js using Firebase UI and Cookie SessionsWhat is a stub in Node.js ?How to validate if input in input field has full width string only using express-validator ?How to validate if input in input field has hexadecimal number only using express-validator ?How to validate if input date (start date) in input field must be before a given date (end date) using express-validator ?How to validate if input in input field has valid hexadecimal color only using express-validator ?How to validate if input in input field must contains a seed word using express-validator ?How to validate if input in input field has integer number only using express-validator ?How to validate if input in input field is a valid date using express-validator ?How to validate if input in input field is divisible by or multiple of a number using express-validator ?How to validate if input in input field has lowercase letters only using express-validator ?Node.js Server Side Rendering (SSR) using EJSHow to validate if input date (end date) in input field must be after a given date (start date) using express-validator ?How to get Trending GitHub Repositories Using Node.js ?How to validate if input in input field has float number only using express-validator ?Difference between Node.js and React.jsNode.js vs Vue.jsHow to validate if input in input field has ASCII characters using express-validator ?How to create Covid19 Country wise status project using REST API ?How to validate if input in input field has alphabets only using express-validator ?How to validate if input in input field has base 32 encoded string using express-validator ?How to validate if input in input field has base64 encoded string using express-validator ?Top 8 Reasons To Learn NodeJS In 2020How Node.js works behind the scene ?Unit Testing of Node.js ApplicationCreating a REST API Backend using Node.js, Express and PostgresHow to compare password and confirm password inputs using express-validator ?How to store password securely in your local/custom database in Node.js ?How to Sign In with raw password when password store in the database are hashed form in Node.js ?How to check if email address is already in use or not using express-validator in Node.js ?NODE_ENV Variables and How to Use Them ?How to delete a record from your local/custom database in Node.js ?How to update a record in your local/custom database in Node.js?How to operate callback based fs.writeFile() method with promises in Node.js ?How to operate callback-based fs.lstat() method with promises in Node.js ?How to make simple PUT request using fetch API by making custom HTTP library ?How to operate callback-based fs.rename() method with promises in Node.js ?How to add unique Id to each record in your local/custom database in Node.js ?How to make PUT request using XMLHttpRequest by making Custom HTTP library ?How to operate callback-based fs.readdir() method with promises in Node.js ?How to add records in your own local/custom database in Node.js ?How to operate callback-based fs.truncate() method with promises in Node.js ?POST request using AJAX by making Custom HTTP libraryHow to find record using any key-value pair information of record in your local/custom database using Node.js ?How to operate callback-based fs.readFile() method with promises in Node.js ?How to operate callback-based fs.mkdir() method with promises in Node.js ?How HTTP POST request work in NodeJS?Global, Process and buffer in Node.jsHow to operate callback-based fs.opendir() method with promises in Node.js ?How to find record by Id from local/custom database in Node.js ?How to check whether a script is running under Node.js or not ?RESTful Routes in Node.jsGet request using AJAX by making Custom HTTP libraryHow to operate callback based fs.appendFile() method with promises in Node.js ?How to work with Node.js and JSON file ?Node.js stats.isBlockDevice() Method from fs.Stats ClassHow to resolve ‘node’ is not recognized as an internal or external command error after installing Node.js ?Difference between process.nextTick() and setImmediate() MethodsImplementing Csurf Middleware in Node.jsRun Python Script using PythonShell from Node.jsHow to display output data in tabular form in Node.js ?How to use Class in Node.js ?How to remove all Global Modules in Node.js ?RESTfull routes on Node.js and MongoDBHow to include Functions from other files in Node.js ?Generating Errors using HTTP-errors module in Node.jsHow to update Node.js and NPM to next version ?What is the meaning of –save for NPM install ?How Base64 encoding and decoding is done in node.js ?How to Display Flash Messages using connect-flash Module in Node.js ?How to Configure Socket.IO with Demo-Chat App in Node.js ?How to send Attachments and Email using nodemailer in Node.js ?What is Reactor Pattern in Node.js ?Parsing form data in express app manually without body-parserCreating Socket.IO Server using Express GeneratorHow to Generate fake data using Faker module in Node.js ?How to copy folder recursively in Node.js ?What is stream and its types in Node.js ?Node.js | Image Upload, Processing and Resizing using Sharp packageHow to handle errors in node.js ?How to take Screenshots in ElectronJS ?Introduction to NPM scriptsLogin form using Node.js and MongoDBHow to run node.js program as an Executable ?Handling User-Agents in Node.jsHow to handle badwords in Node.js ?What is stacktrace and how to print in node.js ?Why Express ‘app’ and ‘server’ files kept separately ?Working Process of Node.jsHow to update NPM ?How to display all files in a directory using Node.js ?Node.js | Open Weather Map API for Weather ForecastsWhat are the various timing features of Node.js ?How to read a file line by line using node.js ?How to use Sequelize in Node.js ?Reading Query Parameters in Node.jsHow to resolve unhandled exceptions in Node.js ?How to convert text to speech in Node.js ?Reading Path Parameters in Node.jsHow to Create a Pre-Filled forms in Node.js ?Body-parser middleware in Node.jsHow to Create Modules in Node.js ?How to get daily weather notification on mobile using Node.js and Twilio API ?What is callback hell in Node.js ?How to Validate Data using express-validator Module in Node.js ?What is the Punycode in Node.js ?Data Scraping for Android Apps using google-play-scraper in Node.jsBest Security Practices in Node.jsHow to Run Synchronous Queries using sync-sql Module in Node.js ?Session Management using express-session Module in Node.jsHow to Validate Data using joi Module in Node.js ?How to Integrate Stripe Payment Gateway in Node.js ?How to Setup Handlebars View Engine in Node.js ?Password Hashing with MD5 module in Node.jsHow to Validate Data using validator Module in Node.js ?How to Set Online SQL Server for Node.js ?How to Send Email using Mailgun API in Node.js ?How to Upload File using formidable module in Node.js ?How to Serve Static Content using Node.js ?How to Setup View Engine in Node.js ?How to write asynchronous function for Node.js ?Which One is Most Demanding Back-End Web Framework between Laravel , NodeJS and Django ?7 Famous Apps Built on NodeJS: Reasons and BenefitsDifference between Fetch and Axios.js for making http requestsDifference between node.js require and ES6 import and exportWhat are the differences between npm and npx ?Sending bulk SMS in Node.js using TwilioHow to install the previous version of node.js and npm ?How to read command line arguments in Node.js ?Difference between npm and yarnHow to check the given path is file or directory in node.js ?How to configure node.js console font ?How to store deployment configuration files in Node.js ?How to update dependency in package.json file ?Difference Between Django and Node.jsHow to print console without trailing newline in Node.js ?How to convert an existing callback to a promise in Node.js ?Creating a simple JSON based API using Node.jsDifference between __dirname and ./ in Node.jsWhat is the difference between –save and –save-dev in Node.js ?Sending SMS using NEXMO API in Node.jsHow To Become A Web Developer in 2020 – A Complete GuideHow to refresh a file in Node.js ?How to get the path of current script using Node.js ?How to read and write JSON file using Node.js ?How to run Cron Jobs in Node.js ?How to use External Modules and NPM in a project ?Steps to Create and Publish NPM packagesThings You Must Know about Node.JSSending bulk emails in Node.js using SendGrid APIFile uploading in Node.jsHow to send email with Nodemailer using Gmail account in Node.js ?Debugging and Testing of a Node ApplicationHow to share code between Node.js and the browser?Design first Application using ExpressBuild a Simple static file web server in NodeIntroduction to Sockets.IO in NodeExpose Functionality from a Node file using exportsSignup Form Using Nodejs and MongoDBEncrypting Data in NodeJSNodejs – Connect Mysql with Node appNodejs | Automatic restart NodeJs server with nodemonNodeJS | Building simple REST API in expressIntroduction about Node.js and MongoDBDockerizing a simple Nodejs appDifference between NodeJS and AngularJSDeploying Node ApplicationsAsynchronous Functions and the Node Event Loop Comment More infoAdvertise with us Next Article NodeJS Introduction K kartik Follow Improve Article Tags : Web Technologies Node.js NodeJS-Questions Similar Reads Node.js Tutorial Node.js is a powerful, open-source, and cross-platform JavaScript runtime environment built on Chrome's V8 engine. It allows you to run JavaScript code outside the browser, making it ideal for building scalable server-side and networking applications.JavaScript was mainly used for frontend developme 4 min read Introduction & Installation NodeJS IntroductionNodeJS is a runtime environment for executing JavaScript outside the browser, built on the V8 JavaScript engine. It enables server-side development, supports asynchronous, event-driven programming, and efficiently handles scalable network applications. NodeJS is single-threaded, utilizing an event l 5 min read Node.js Roadmap: A Complete GuideNode.js has become one of the most popular technologies for building modern web applications. It allows developers to use JavaScript on the server side, making it easy to create fast, scalable, and efficient applications. Whether you want to build APIs, real-time applications, or full-stack web apps 6 min read How to Install Node.js on LinuxInstalling Node.js on a Linux-based operating system can vary slightly depending on your distribution. This guide will walk you through various methods to install Node.js and npm (Node Package Manager) on Linux, whether using Ubuntu, Debian, or other distributions.PrerequisitesA Linux System: such a 6 min read How to Install Node.js on WindowsInstalling Node.js on Windows is a straightforward process, but it's essential to follow the right steps to ensure smooth setup and proper functioning of Node Package Manager (NPM), which is crucial for managing dependencies and packages. This guide will walk you through the official site, NVM, Wind 6 min read How to Install NodeJS on MacOSNode.js is a popular JavaScript runtime used for building server-side applications. It’s cross-platform and works seamlessly on macOS, Windows, and Linux systems. In this article, we'll guide you through the process of installing Node.js on your macOS system.What is Node.jsNode.js is an open-source, 6 min read Node.js vs Browser - Top Differences That Every Developer Should KnowNode.js and Web browsers are two different but interrelated technologies in web development. JavaScript is executed in both the environment, node.js, and browser but for different use cases. Since JavaScript is the common Programming language in both, it is a huge advantage for developers to code bo 6 min read NodeJS REPL (READ, EVAL, PRINT, LOOP)NodeJS REPL (Read-Eval-Print Loop) is an interactive shell that allows you to execute JavaScript code line-by-line and see immediate results. This tool is extremely useful for quick testing, debugging, and learning, providing a sandbox where you can experiment with JavaScript code in a NodeJS enviro 5 min read Explain V8 engine in Node.jsThe V8 engine is one of the core components of Node.js, and understanding its role and how it works can significantly improve your understanding of how Node.js executes JavaScript code. In this article, we will discuss the V8 engine’s importance and its working in the context of Node.js.What is a V8 7 min read Node.js Web Application ArchitectureNode.js is a JavaScript-based platform mainly used to create I/O-intensive web applications such as chat apps, multimedia streaming sites, etc. It is built on Google Chrome’s V8 JavaScript engine. Web ApplicationsA web application is software that runs on a server and is rendered by a client browser 3 min read NodeJS Event LoopThe event loop in Node.js is a mechanism that allows asynchronous tasks to be handled efficiently without blocking the execution of other operations. It:Executes JavaScript synchronously first and then processes asynchronous operations.Delegates heavy tasks like I/O operations, timers, and network r 5 min read Node.js Modules , Buffer & StreamsNodeJS ModulesIn NodeJS, modules play an important role in organizing, structuring, and reusing code efficiently. A module is a self-contained block of code that can be exported and imported into different parts of an application. This modular approach helps developers manage large projects, making them more scal 6 min read What are Buffers in Node.js ?Buffers are an essential concept in Node.js, especially when working with binary data streams such as files, network protocols, or image processing. Unlike JavaScript, which is typically used to handle text-based data, Node.js provides buffers to manage raw binary data. This article delves into what 4 min read Node.js StreamsNode.js streams are a key part of handling I/O operations efficiently. They provide a way to read or write data continuously, allowing for efficient data processing, manipulation, and transfer.\Node.js StreamsThe stream module in Node.js provides an abstraction for working with streaming data. Strea 4 min read Node.js Asynchronous ProgrammingAsync Await in Node.jsAsync and await in Node are the modern way of handling asynchronous operations more efficiently. These are powerful keywords that replaces the traditional callback and Promise chaining approaches.Handling Asynchronous Operations Before Async AwaitCallbacksBefore Node version 7.6, the callbacks were 3 min read Promises in NodeJSPromises are a fundamental concept in asynchronous programming in JavaScript, especially in NodeJS, where non-blocking I/O operations are key to performance. Promises allow us to handle asynchronous operations more efficiently than traditional callback functions, leading to cleaner, more readable co 8 min read How to Handle Errors in Node.js ?Node.js is a JavaScript extension used for server-side scripting. Error handling is a mandatory step in application development. A Node.js developer may work with both synchronous and asynchronous functions simultaneously. Handling errors in asynchronous functions is important because their behavior 4 min read Exception Handling in Node.jsException handling refers to the mechanism by which the exceptions occurring in a code while an application is running is handled. Node.js supports several mechanisms for propagating and handling errors. There are different methods that can be used for exception handling in Node.js: Exception handl 3 min read Node.js NPMNodeJS NPMNPM (Node Package Manager) is a package manager for NodeJS modules. It helps developers manage project dependencies, scripts, and third-party libraries. By installing NodeJS on your system, NPM is automatically installed, and ready to use.It is primarily used to manage packages or modules—these are 6 min read Steps to Create and Publish NPM packagesIn this article, we will learn how to develop and publish your own npm package (also called an NPM module). There are many benefits of NPM packages, some of them are listed below: Reusable codeManaging code (using versioning)Sharing code The life-cycle of an npm package takes place like below: Modu 7 min read Introduction to NPM scriptsNPM is a Node Package Manager. It is the world's largest Software Registry. This registry contains over 800,000 code packages. Many Open-source developers use npm to share software. Many organizations also use npm to manage private development. "npm scripts" are the entries in the scripts field of t 2 min read Node.js package.jsonThe package.json file is the heart of Node.js system. It is the manifest file of any Node.js project and contains the metadata of the project. The package.json file is the essential part to understand, learn and work with the Node.js. It is the first step to learn about development in Node.js.What d 4 min read What is package-lock.json ?package-lock.json is a file that is generated when we try to install the node. It is generated by the Node Package Manager(npm). package-lock.json will ensure that the same versions of packages are installed. It contains the name, dependencies, and locked version of the project. It will check that s 3 min read Node.js Deployments & CommunicationNode DebuggingDebugging is an essential part of software development that helps developers identify and fix errors. This ensures that the application runs smoothly without causing errors. NodeJS is the JavaScript runtime environment that provides various debugging tools for troubleshooting the application.What is 3 min read How to Perform Testing in Node.js ?Testing is a method to check whether the functionality of an application is the same as expected or not. It helps to ensure that the output is the same as the required output. How Testing can be done in Node.js? There are various methods by which tasting can be done in Node.js, but one of the simple 2 min read Unit Testing of Node.js ApplicationNode.js is a widely used javascript library based on Chrome's V8 JavaScript engine for developing server-side applications in web development. Unit Testing is a software testing method where individual units/components are tested in isolation. A unit can be described as the smallest testable part of 5 min read NODE_ENV Variables and How to Use Them ?Introduction: NODE_ENV variables are environment variables that are made popularized by the express framework. The value of this type of variable can be set dynamically depending on the environment(i.e., development/production) the program is running on. The NODE_ENV works like a flag which indicate 2 min read Difference Between Development and Production in Node.jsIn this article, we will explore the key differences between development and production environments in Node.js. Understanding these differences is crucial for deploying and managing Node.js applications effectively. IntroductionNode.js applications can behave differently depending on whether they a 3 min read Best Security Practices in Node.jsThe security of an application is extremely important when we build a highly scalable and big project. So in this article, we are going to discuss some of the best practices that we need to follow in Node.js projects so that there are no security issues at a later point of time. In this article, we 4 min read Deploying Node.js ApplicationsDeploying a NodeJS application can be a smooth process with the right tools and strategies. This article will guide you through the basics of deploying NodeJS applications.To show how to deploy a NodeJS app, we are first going to create a sample application for a better understanding of the process. 5 min read How to Build a Microservices Architecture with NodeJSMicroservices architecture allows us to break down complex applications into smaller, independently deployable services. Node.js, with its non-blocking I/O and event-driven nature, is an excellent choice for building microservices. How to Build a Microservices Architecture with NodeJS?Microservices 3 min read Node.js with WebAssemblyWebAssembly, often abbreviated as Wasm, is a cutting-edge technology that offers a high-performance assembly-like language capable of being compiled from various programming languages such as C/C++, Rust, and AssemblyScript. This technology is widely supported by major browsers including Chrome, Fir 3 min read Resources & ToolsNode.js Web ServerA NodeJS web server is a server built using NodeJS to handle HTTP requests and responses. Unlike traditional web servers like Apache or Nginx, which are primarily designed to give static content, NodeJS web servers can handle both static and dynamic content while supporting real-time communication. 6 min read Node Exercises, Practice Questions and SolutionsNode Exercise: Explore interactive quizzes, track progress, and enhance coding skills with our engaging portal. Ideal for beginners and experienced developers, Level up your Node proficiency at your own pace. Start coding now! #content-iframe { width: 100%; height: 500px;} @media (max-width: 768px) 4 min read Node.js ProjectsNode.js is one of the most popular JavaScript runtime environments widely used in the software industry for projects in different domains like web applications, real-time chat applications, RESTful APIs, microservices, and more due to its high performance, scalability, non-blocking I/O, and many oth 9 min read NodeJS Interview Questions and AnswersNodeJS is one of the most popular runtime environments, known for its efficiency, scalability, and ability to handle asynchronous operations. It is built on Chrome’s V8 JavaScript engine for executing JavaScript code outside of a browser. It is extensively used by top companies such as LinkedIn, Net 15+ min read Like