Node.js - Hello World Example Tutorial

You can run Node.js application an console based or web-based application. Console based application will run your system terminal and a web-based application will use an inbuilt web server to make an application accessible on the web browser.

Console-based Hello World Example

Use the Node.js console module to print output on your system console. Create a JavaScript file nodejs_hello_console.js using the below content.

console.log('Hello World');

1	console.log('Hello World');

Execute your script using the node

node nodejs_hello_console.js

[output]
Hello World!

Web-based Hello World Example

A Node.js web application is build with 3 parts.

Import module to create web server
Create a web server
Read client requests and send reponse back to client

Below is the sample application uses http module. http module creates a web server similar to Apache or Nginx web servers. Now create a server with specified host and port. Use used 0.0.0.0 host address means it will listen on all interfaces attached to the system.

Create a JavaScript file nodejs_hello_web.js and add the following content.

const http = require('http');

const host = '0.0.0.0';
const port = 3000;

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World!');
});

server.listen(port, host, () => {
   console.log('Web server running at http://%s:%s',host,port );
});

const http = require('http');

const host = '0.0.0.0';

const port = 3000;

const server = http.createServer((req, res) => {

res.statusCode = 200;

res.setHeader('Content-Type', 'text/plain');

res.end('Hello World!');

});

server.listen(port, host, () => {

console.log('Web server running at http://%s:%s',host,port );

});

Execute the script using node. It will start a web server on specified port and host.

node nodejs_hello_web.js

[output]
Web server running at http://0.0.0.0:3000

For example, above script started a web server on port 3000. Visit your server on a defined port in the web browser. It will show you the result like below.

hello world, node, node.js, nodejs