Node.js is an open-source and cross-platform JavaScript runtime environment. It is a popular tool for almost any kind of project!
Node.js runs the V8 JavaScript engine, the core of Google Chrome, outside of the browser. This allows Node.js to be very performant.
A Node.js app runs in a single process, without creating a new thread for every request. Node.js provides a set of asynchronous I/O primitives in its standard library that prevent JavaScript code from blocking and generally, libraries in Node.js are written using non-blocking paradigms, making blocking behavior the exception rather than the norm.
When Node.js performs an I/O operation, like reading from the network, accessing a database or the filesystem, instead of blocking the thread and wasting CPU cycles waiting, Node.js will resume the operations when the response comes back.
This allows Node.js to handle thousands of concurrent connections with a single server without introducing the burden of managing thread concurrency, which could be a significant source of bugs.
Node.js has a unique advantage because millions of frontend developers that write JavaScript for the browser are now able to write the server-side code in addition to the client-side code without the need to learn a completely different language.
In Node.js the new ECMAScript standards can be used without problems, as you don't have to wait for all your users to update their browsers - you are in charge of deciding which ECMAScript version to use by changing the Node.js version, and you can also enable specific experimental features by running Node.js with flags.
An Example Node.js Application
The most common example Hello World of Node.js is a web server:
const { createServer } = require('node:http');const hostname = '127.0.0.1';const port = 3000;const server = createServer((req, res) => { res.statusCode = 200; res.setHeader('Content-Type', 'text/plain'); res.end('Hello World');});server.listen(port, hostname, () => { console.log(`Server running at http://${hostname}:${port}/`);});
To run this snippet, save it as a server.js file and run node server.js in your terminal.If you use mjs version of the code, you should save it as a server.mjs file and run node server.mjs in your terminal.
This code first includes the Node.js http module.
Node.js has a fantastic standard library, including first-class support for networking.
The createServer() method of http creates a new HTTP server and returns it.
The server is set to listen on the specified port and host name. When the server is ready, the callback function is called, in this case informing us that the server is running.
Whenever a new request is received, the request event is called, providing two objects: a request (an http.IncomingMessage object) and a response (an http.ServerResponse object).
Those 2 objects are essential to handle the HTTP call.
The first provides the request details. In this simple example, this is not used, but you could access the request headers and request data.
The second is used to return data to the caller.
In this case with:
we set the statusCode property to 200, to indicate a successful response.
We set the Content-Type header:
res.setHeader('Content-Type', 'text/plain');
and we close the response, adding the content as an argument to end():
res.end('Hello World\n');
FAQs
if you have a prior knowledge of html,java script then learning nodejs will take you at max 4–5 days. however with the problems that you will face during your projects,you will explore a lot of new things. Don't just waste too much time on learning the syntax.
Is node js hard to learn if you know JavaScript? ›
If you already have experience using JavaScript, then Node is fairly easy to pick up. You're now going to be able to use that same knowledge to help you fast-track into learning the back-end also, and become a full-stack developer. And if you're not using JavaScript yet, you'll learn it as you learn to use Node.
How much JavaScript should I know in order to learn node JS? ›
Node is written in JavaScript, so you should start by learning JavaScript. This means understanding scopes, functions, closures, module patterns, classes, promises, and callbacks, as well as the capabilities of Strings, Numbers, Arrays, Objects, Sets, and Maps.
Is Node.js worth learning in 2024? ›
Statistics of Node JS Usages You Must Know in 2024. With more than 6.3 million websites using Node. js, it has become the most widely used tool for web development in the United States. This statistic gives us a good outlook for the use of Node.
Can I learn NodeJS in 1 week? ›
It takes around 3 months to fully learn Node JS and be able to build a functional full-stack application. If you already know some other programming, you can get the basics down within a few week's time. This is because there are so many moving parts that go into building a working app such as a social network.
Can I learn NodeJS in 2 weeks? ›
Average learning time for Node. js depends on the learner's JavaScript experience, with skilled coders needing about a week of study. A prerequisite for learning Node. js is having a substantial knowledge of JavaScript.
Why node js is so hard? ›
Since Node. js is an advanced programming skill, the more computer science experience and training you have, the easier it will be to learn. The biggest hurdle for Node. js students is already surmounted because it is learning HTML/CSS and JavaScript, which is required to start learning Node.
What is the salary of a node JS developer? ›
Node Js Developer Salaries in India
The average salary for Node Js Developer is ₹5,40,000 per year in the India. The average additional cash compensation for a Node Js Developer in the India is ₹40,000, with a range from ₹4,500 - ₹51,437.
How long does it take to learn node JS for beginners? ›
If you have a good programming background and know JavaScript well, you don't have to worry about how long it will take to learn Node. js. It will take just a few days. But if you have a strong experience in development but lack knowledge in JavaScript, then it may take two to six weeks to learn node.
Can I start NodeJS without knowing JavaScript? ›
Learning Node. js requires solid knowledge of JavaScript, HTML, and CSS, making it moderately difficult for those not already versed in these languages.
Node. js is a popular choice for back-end development because of its performance, versatility, and large developer community. It provides a fast and efficient platform for building server-side applications, making it a great choice for full-stack development.
How to learn NodeJS quickly? ›
Like other programming languages you learn how to print “Hello World!” and then you start learning the basic concepts like variables, data types, operators, functions, etc in JavaScript. Make sure that you understand all these concepts in JavaScript very well before you move to build the actual application in Node JS.
Is Node JS declining? ›
It's becoming one of many viable options, rather than the go-to solution it once was. This doesn't diminish its value but reflects the dynamic nature of the tech world, where diversity of tools and approaches is key to innovation. In conclusion, while Node. js faces stiff competition, it's far from being sidelined.
Will Node JS be discontinued? ›
js 16 is at the end of its life, it just means it won't get updates after September 2023. But newer versions like Node. js 18 are still being worked on and updated.
Does Netflix still use Node JS? ›
Earlier, Netflix was using Java on the back end and JavaScript on the front end, which required the developers to be proficient with languages. As a result, they had to do double work for error handling, activity tracking, and debugging. Netflix is now among companies using Node.
How long does NodeJS take to learn? ›
If you have a good programming background and know JavaScript well, you don't have to worry about how long it will take to learn Node. js. It will take just a few days. But if you have a strong experience in development but lack knowledge in JavaScript, then it may take two to six weeks to learn node.
Can I learn JavaScript in 3 days? ›
JavaScript Intermediate Concepts
2 – 3 days if you are coming from another programming language background. Learning intermediate concepts will take one week if you are a beginner.
How long does it take to learn three JS? ›
Become a Three.js developer. Everything you need in one place: 93 hours of video to go from absolute beginner to advanced Three.js developer.
How can I learn NodeJS fast? ›
Like other programming languages you learn how to print “Hello World!” and then you start learning the basic concepts like variables, data types, operators, functions, etc in JavaScript. Make sure that you understand all these concepts in JavaScript very well before you move to build the actual application in Node JS.
