express js hello world code example

Example 1: nodejs hello world

const http = require('http');

const hostname = '127.0.0.1';
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, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`);
});

Example 2: express hello world

//to run : node filename.js
const express = require('express')
const app = express()
const port = 3000

app.get('/', (req, res) => res.send('Hello World!'))

app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))

//visit localhost:3000
// assuming you have done 1) npm init 2) npm install express

Example 3: node js express

basic server

const express =require('express');
const app = express();
const PORT = 5000;


app.get('/',(req,res)=>{
   res.json({message: 'Welcome to the backend'})
})


app.listen(PORT ,()=>console.log(`Connected to ${PORT}`)

Example 4: require express server.js

const express = require('express')const app = express() app.get('/', function (req, res) {  res.send('Hello World')}) app.listen(3000)