Express sends us two objects in this
callback, which we called
req and res, they represent the Request and the Response
objects.- Request is the HTTP request. It gives us all the request information, including the request parameters, the headers, the body of the request, and more.
- Response is the HTTP response object that we’ll send to the client.
Request Object in Express:
request.url :
URL of current object
request.method : GET | POST
request.headers : Used to read headers sent from
browser to server
request.query : Used to read query string
parameters in the form of object [GET request] Ex: {username:”abc”,
password:”xyz”}
request.body : Used to read query string
parameters in the form of object [POST request]. Ex: {username:”abc”,
password:”xyz”}
Response Object in
Express:
response.write() : Passes string values to browser
response.end() : Ends of the
response
response.headers() : Send response headers
from server to browser
response.status() :
Used to set status code
response.sendFile() :
Used to read content of file and send the same response to browser
response.send() :
Used to read send string/object to browser
response.json() : Used to read send json data to browser
Lets
create an application that will describe Request and Response Objects:
reqRes.js
const express = require('express');
const app = express();
app.get('/', (req, res) => {
console.log(req.url);
console.log(req.method);
console.log(req.headers);
console.log(req.query);
console.log(req.body);
res.header('content-type', 'text/html');
res.status(500);
res.write('This is a reply from server<br>');
res.write('This is another reply from server');
res.end();
res.send('This is reply from server to browser using send()');
// But you can send only one response using res.send()
res.sendFile(__dirname + '/login.html');
res.json([
{ id: 1, name: "pankaj" },
{ id: 2, name: "sachin" },
]);
});
app.listen(3000, () => {
console.log('Server is Running on 3000');
});
Output : http://localhost:3000/?x=10&y=20
Request Objects
Request Objects
Response Objects
