express node documentation code example

Example 1: require express server.js

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

Example 2: http header express

app.get('/', (req, res) => {
  req.header('User-Agent')
})
// Use the Request.header() method to access
//one individual request header’s value

Example 3: express js

Express.js, or simply Express, is a web application framework for Node.js,
released as free and open-source software under the MIT License.

It is designed for building web applications and APIs.
It has been called the de facto standard server framework for Node.js.