How are the req and res objects created in Node.js? - node.js

Question

I understand what the req and res objects contain, what they are used for, and when they are created, but I was wondering how they are created.

Answer 1

The req and res objects that you are referring to come from an npm package called express. Express is a lightweight package that allows you to handle HTTP requests on your node server.
Below is a small example of how to use the package with some example HTTP endpoints.
In the example, I also use a package called 'body-parser' this package is used to parse any HTTP requests with a JSON body. The package puts the parsed body into the req object at the key body, as can be seen in the code example.
const express = require('express');
const bodyParser = require('body-parser');
const app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.get('/', (req, res) => {
// Handle GET / request here
});
app.post('/', (req, res) => {
// Handle POST / request here
// Get body of request
var body = req.body;
});
app.listen(8080, () => console.log('Listening on port 8080'));

Answer 2

req and res are the component of Express framework of Node package manager(npm) and is used to respond as per the request created by the user.
//To print Date as string
const express = require("express");
const bodyparser = require("body-Parser");
const app = express();
app.get("/", function(req, res) {
var today = new Date();
var options = {
weekday: "long",
year: "numeric",
month: "long",
day: "numeric",
};
var day = today.toLocaleDateString("en-US", options);
res.render("list", {
kindOfDay: day
});
});
app.post("/", function(req, res) {
var item = req.body.selectSection;
items.push(item);
res.redirect("/");
});
app.listen("3000", function() {
console.log(" the server is runnimg in port 3000");
});