1. Create a packages.json: $ npm init
2. Install Express and save it in packages: $ npm install express –save

var express = require('express');

var app = express();

app.listen(3000, function() {
  console.log("server started on Port 3000");
})

Take the get to de home (using request and the response):

app.get('/', fucntion(req, res) {
  res.send('Hello world');
});

app.post('/users/add', function(req, res){
  console.log(req.body.firstName);
  res.redirect('/');
});

app.delete('/users/:id', function(req, res) {
  console.log(req.params.id);
});

Return a variable in its json format: res.json(person);

use is important to put it before any request.

var logger = function (req, res, next){
  console.log('Logging');
  next();
}
app.use(logger);

Set the view engine

app.set('view engine', 'ejs');
// with this we can render views:
res.render('index');

Set the views folder:

app.set('views', path.join(__dirname, 'views');

Set global variables

app.use(function(req, res, next) {
  res.locals.errors = null;
  next();
});

Add a “public” path:

var path = require('path');
app.use(express.static(path.join(__dirname, 'public'));

I generally use 1 file per route and put all my routing files in a routes folder and leverage the Router available in express.

A route file could look like this:

var express = require('express');
var router = express.Router();
router.get('/', function (req, res) {
    res.send('Hello World!');
});

module.exports = router;

Then in the app file, simply add:

var example = require('./routes/example');
app.use('/', example);

The routes in the routing file are relative to the route you declare in app.use.