JAVASCRIPT

node express app.listen at specific port & host

const express = require('express');
const app = express();
app.listen('9000','0.0.0.0',()=>{
      console.log("server is listening on 9000 port");
})

express js app server listen on port

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

var listener = app.listen(8888, function(){
    console.log('Listening on port ' + listener.address().port); //Listening on port 8888
});