why is createServer() considered not a function?
createServer is a function of http so it should be:
const express = require('express');const http = require('http');const app = express();app.get('/', function (req, res) { res.send('hi');});const server = http.createServer(app).listen(8080, function(err) { if (err) { console.log(err); } else { const host = server.address().address; const port = server.address().port; console.log(`Server listening on ${host}:${port}`); }});P.S. Installing express globally is a bad idea