Simplest possible Express application

simple-express.js

// simplest possible express app
var http = require('http');
var express = require('express');

var app = express();

// local database. When you restart the express server, the values will reset to original
let db = [
    {
        name: "Mike",
        age: 23,
    },
    {
        name: "Steven",
        age: 26,
    }
]

app.get("/person", function(req, res) {
    
    // grab query parameters from request
    const dbIndex = req.query.index;
    
    // find that person in the database variable able
    let person = db[dbIndex];
    
    // return the person we are looking for
    return res.json(person);
});

http.createServer(app).listen(4000, function() {
    console.log("Express server listening on port 4000");
});