How to I get the GET (query string) variables in Express.js on Node.js?

Answer

First equation to get the variable string (value.query.id) so
var express = require('express');
var app = express();

app.get('/', function(req, res){
res.send('id: ' + req.query.id);
});

app.listen(3000);

otherwise we can get another
equation
var url = require('url');
var url_parts = url.parse(request.url, true);
var query = url_parts.query;