Request body transformation in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to parse JSON request bodies in Express.

Express

const express = require('express');
const app = express();

app.use(express.[1]());

app.post('/data', (req, res) => {
  res.send(req.body);
});

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

Aurlencoded

Bjson

Ctext

Draw

Attempts:

3 left

💡 Hint

Common Mistakes

Using express.urlencoded() instead of express.json() for JSON data.

Forgetting to add the middleware before route handlers.

Express uses express.json() middleware to parse JSON request bodies.

2fill in blank

medium

Complete the code to transform the request body by adding a new property before sending the response.

Express

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

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

Aresult

Btype

Cprocessed

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using a value as a property name instead of a key.

Trying to modify req.body directly without assigning to a variable.

We add a new property named status to the request body object.

3fill in blank

hard

Fix the error in the code to correctly parse URL-encoded form data.

Express

app.use(express.[1]({ extended: true }));

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

Ajson

Btext

Curlencoded

Draw

Attempts:

3 left

💡 Hint

Common Mistakes

Using express.json() for form data.

Omitting the middleware and causing req.body to be undefined.

To parse URL-encoded form data, use express.urlencoded() middleware.

4fill in blank

hard

Fill both blanks to create a middleware that transforms the request body by uppercasing a 'name' property.

Express

app.use((req, res, next) => {
  if (req.body && req.body.[1]) {
    req.body.[2] = req.body.name.toUpperCase();
  }
  next();
});

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

Aname

Busername

Cuser

DName

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong property name in the condition.

Not calling next() to continue the middleware chain.

The middleware checks if req.body.name exists, then creates a new property username with the uppercase value.

5fill in blank

hard

Fill all three blanks to create a route that transforms the request body by adding a timestamp and sending the modified object.

Express

app.post('/submit', (req, res) => {
  const data = req.body;
  data.[1] = new Date().[2]();
  res.[3](data);
});

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

Atimestamp

BtoISOString

Cjson

Dnow

Attempts:

3 left

💡 Hint

Common Mistakes

Using Date.now() which returns a number instead of a string.

Forgetting to send the response with res.json().

The code adds a timestamp property with the current date in ISO string format, then sends the data as JSON.