var express = require('express')
var app = express()

app.get('/', function(req,res) {
  res.send('Hello World!')
})

app.listen(8081, function() {
  console.log('app listening on port 8081!')
})


const express = require('express')
const app = express()
const port = 3000

app.get('/', function(req,res) {
  res.send('Hello World!')
})

app.listen(port, function() {
  console.log(`Example app listening on port ${port}!`)
})


Update index.js