var express = require('express');

var app = express();

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

app.listen(8080, function () {
  console.log('Example app listening on port 8080!');
});
var express = require('express');

var app = express();

var port = process.env.PORT || 8080

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

app.listen(port, function () {
  console.log('Example app listening on port '+ port +'!');
});
Add variable for port.