Why Express for Node.js web servers - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a basic Express server that listens on port 3000.

Express

const express = require('express');
const app = express();
app.get('/', (req, res) => {
  res.send('Hello World!');
});
app.listen([1], () => {
  console.log('Server is running');
});

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

A8080

B5000

C3000

D80

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 80 which requires admin rights

Using a string instead of a number

The number 3000 is the common default port for Express servers in development.

2fill in blank

medium

Complete the code to add middleware that parses JSON bodies in Express.

Express

const express = require('express');
const app = express();
app.use([1]);
app.post('/data', (req, res) => {
  res.json(req.body);
});

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

Aexpress.json()

Bexpress.urlencoded({ extended: true })

Cexpress.static('public')

Dexpress.raw()

Attempts:

3 left

💡 Hint

Common Mistakes

Using urlencoded middleware for JSON

Using static middleware which serves files

express.json() middleware parses incoming JSON requests and puts the parsed data in req.body.

3fill in blank

hard

Fix the error in the route handler to send a JSON response with a message.

Express

app.get('/hello', (req, res) => {
  res.[1]({ message: 'Hi there!' });
});

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

AsendFile

Bjson

Crender

Dredirect

Attempts:

3 left

💡 Hint

Common Mistakes

Using sendFile which expects a file path

Using render without a view engine

res.json() sends a JSON response. Other methods serve files, render views, or redirect.

4fill in blank

hard

Fill both blanks to create a route that responds to PUT requests at '/update'.

Express

app.[1]('/update', (req, res) => {
  res.status([2]).send('Update received');
});

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

Aput

Bpost

Cget

D200

Attempts:

3 left

💡 Hint

Common Mistakes

Using GET or POST instead of PUT

Using status codes like 404 or 500

PUT is the HTTP method for update actions. Status 200 means success.

5fill in blank

hard

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

Express

app.use((req, res, [1]) => {
  console.log(req.[2] + ' ' + req.[3]);
  next();
});

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

Anext

Bmethod

Curl

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to call next()

Using res.send instead of next

Logging wrong properties

Middleware functions receive next to pass control. req.method and req.url give request info.