app listen express

1//to run : node filename.js
2const express = require('express')
3const app = express()
4const port = 3000
5
6app.get('/', (req, res) => res.send('Hello World!'))
7
8app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))
9
10//visit localhost:3000
11// assuming you have done 1) npm init 2) npm install express

1const express = require('express')
2const app = express()
3const port = 3000
4
5app.get('/', (req, res) => res.send('Hello World!'))
6
7app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))
8

1
2const express = require('express')
3const app = express()
4const port = 3000
5
6app.get('/', (req, res) => {
7  res.send('Hello World!')
8})
9
10app.listen(port, () => {
11  console.log(`Example app listening at http://localhost:${port}`)
12})
13
14

1const express = require('express')const app = express() app.get('/', function (req, res) {  res.send('Hello World')}) app.listen(3000)

1app.get('/', (req, res) => {
2  req.header('User-Agent')
3})
4// Use the Request.header() method to access
5//one individual request header’s value