# test installation
command -v nvm
nvm

# check version
nvm ls
       v18.20.1
       v20.12.1
->       system
default -> 20 (-> v20.12.1)
iojs -> N/A (default)
unstable -> N/A (default)
node -> stable (-> v20.12.1) (default)
stable -> 20.12 (-> v20.12.1) (default)
lts/* -> lts/iron (-> v20.12.1)
lts/argon -> v4.9.1 (-> N/A)
lts/boron -> v6.17.1 (-> N/A)
lts/carbon -> v8.17.0 (-> N/A)
lts/dubnium -> v10.24.1 (-> N/A)
lts/erbium -> v12.22.12 (-> N/A)
lts/fermium -> v14.21.3 (-> N/A)
lts/gallium -> v16.20.2 (-> N/A)
lts/hydrogen -> v18.20.1
lts/iron -> v20.12.1

# check node version
node --version
v20.12.1

# install LTS
nvm install --lts
Installing latest LTS version.
Now using node v20.14.0 (npm v10.7.0)

# check version
nvm ls

# check node version
node --version
v20.14.0

# Show installed Nodes
nvm ls
# Show available versions
nvm ls-remote
# Install latest version
nvm install node
# Install LTS version
nvm install --lts
# Install a specific version (list available -> example 16.20.2)
nvm install 16.20.2
# Use a specific version
nvm use 16.20.2
# Show npm version
npm --version

    
    
    


    
Hello, World!
    
This is a simple HTML page served by Node.js.

const http = require('http');
const fs = require('fs');
const path = require('path');

const hostname = '127.0.0.1';
const port = 3000;

const server = http.createServer((req, res) => {
    if (req.method === 'GET' && req.url === '/') {
        const filePath = path.join(__dirname, 'index.html');
        fs.readFile(filePath, (err, data) => {
            if (err) {
                res.statusCode = 500;
                res.setHeader('Content-Type', 'text/plain');
                res.end('Internal Server Error');
            } else {
                res.statusCode = 200;
                res.setHeader('Content-Type', 'text/html');
                res.end(data);
            }
        });
    } else {
        res.statusCode = 404;
        res.setHeader('Content-Type', 'text/plain');
        res.end('Not Found');
    }
});

server.listen(port, hostname, () => {
    console.log(`Server running at http://${hostname}:${port}/`);
});

node server.js

curl localhost:3000
http localhost:3000

npm install ws

    
    
    


    
WebSocket Example
    
Connecting...
    

const http = require('http');
const fs = require('fs');
const path = require('path');
const WebSocket = require('ws');

const hostname = '127.0.0.1';
const port = 3000;

// Create HTTP server
const server = http.createServer((req, res) => {
    if (req.method === 'GET' && req.url === '/') {
        const filePath = path.join(__dirname, 'index.html');
        fs.readFile(filePath, (err, data) => {
            if (err) {
                res.statusCode = 500;
                res.setHeader('Content-Type', 'text/plain');
                res.end('Internal Server Error');
            } else {
                res.statusCode = 200;
                res.setHeader('Content-Type', 'text/html');
                res.end(data);
            }
        });
    } else {
        res.statusCode = 404;
        res.setHeader('Content-Type', 'text/plain');
        res.end('Not Found');
    }
});

// Create WebSocket server
const wss = new WebSocket.Server({ server });

wss.on('connection', ws => {
    console.log('Client connected');

    ws.on('message', message => {
        console.log(`Received: ${message}`);
        ws.send('Hello Client');
    });

    ws.on('close', () => {
        console.log('Client disconnected');
    });
});

server.listen(port, hostname, () => {
    console.log(`Server running at http://${hostname}:${port}/`);
});

node server.js

curl localhost:3000

http localhost:3000

const socket = new WebSocket('wss://symmetrical-disco-g454xqrq9pqvfw6pr-3000.app.github.dev/:3000');

const socket = new WebSocket('wss://' + location.host + '/:3000');

npm install -g wscat

wscat -c ws://localhost:3000

Connected (press CTRL+C to quit)
> hello
< Hello Client

[...]
     ws.on('message', message => {
        console.log(`Received: ${message}`);
        ws.send('Hello ' + message);
    });
[...]

    
    
    
    


    
WebSocket Chat Example
    
Connecting...
    

    

        

        

            
        
        

            
            send