Explain some third-party middleware provided by Express.js.

Express.js - Interview Questions

Third-party Middleware: There are many third-party middleware available such as :

* Body-parser

* Cookie-parser

* Mongoose

* Sequelize

* Cors

* Express-validator

To handle HTTP POST requests in Express.js version 4 and above, we have to install a middleware module called body-parser. Body-parser extracts the entire body portion of an incoming request stream and exposes it on req. body, The Middleware was a part of Express.js earlier, but now you have to install it separately. You can install it by using the following command :

npm install MODULE_NAME

You can load it by using requires and used later:

See the Example :

var bodyParser = require('body-parser');  
app.use(bodyParser.json());  
app.use(bodyParser.urlencoded({ extended: false }))  
Note: You can use multiple middleware as an array on a single route.

See the Example :

var middlewareArray = [middleware1, middleware2]  
app.get('/home', middlewareArray, function (req, res, next) {  
  //Code snippets  
})