Router level middleware in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a router-level middleware that logs the request method.

Express

const express = require('express');
const router = express.Router();

router.use(function(req, res, next) {
  console.log(req.[1]);
  next();
});

Drag options to blanks, or click blank then click option'

Apath

Bmethod

Curl

Dbody

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.url instead of req.method

Trying to log req.body in middleware without parsing

The req.method property contains the HTTP method of the request, such as GET or POST.

2fill in blank

medium

Complete the code to mount the router-level middleware on the '/users' path.

Express

const express = require('express');
const app = express();
const router = express.Router();

app.[1]('/users', router);

Drag options to blanks, or click blank then click option'

Ause

Bget

Cpost

Dlisten

Attempts:

3 left

💡 Hint

Common Mistakes

Using app.get instead of app.use

Trying to use app.listen to mount middleware

The app.use() method mounts middleware or routers on a path.

3fill in blank

hard

Fix the error in the router-level middleware to correctly handle errors.

Express

router.use(function(err, req, res, [1]) {
  console.error(err.stack);
  res.status(500).send('Something broke!');
});

Drag options to blanks, or click blank then click option'

Anext

Bdone

Ccallback

Dhandle

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the fourth argument

Naming the fourth argument incorrectly

Error-handling middleware in Express must have four arguments: err, req, res, next. The next argument is required even if not used.

4fill in blank

hard

Fill both blanks to create a router-level middleware that only applies to POST requests on '/submit'.

Express

router.[1]('/submit', function(req, res, next) {
  console.log('POST to /submit');
  [2]();
});

Drag options to blanks, or click blank then click option'

Apost

Bget

Cnext

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Using router.get instead of router.post

Calling res.send instead of next()

The router.post method handles POST requests. Calling next() passes control to the next middleware.

5fill in blank

hard

Fill all three blanks to create a router-level middleware that logs the request URL, method, and then calls next.

Express

router.use(function(req, res, [1]) {
  console.log('URL:', req.[2]);
  console.log('Method:', req.[3]);
  [1]();
});

Drag options to blanks, or click blank then click option'

Anext

Burl

Cmethod

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Using res.send instead of next

Mixing up url and method properties

The middleware function receives req, res, next. The req.url and req.method properties give the URL and HTTP method. Calling next() continues the middleware chain.