req.headers for HTTP headers in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access HTTP headers in an Express route.

Express

app.get('/info', (req, res) => {
  const headers = req.[1];
  res.send(headers);
});

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

Aquery

Bbody

Cparams

Dheaders

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.body instead of req.headers

Using req.params or req.query which are for URL parts

The req.headers object contains all HTTP headers sent by the client.

2fill in blank

medium

Complete the code to read the 'user-agent' header from the request.

Express

app.get('/agent', (req, res) => {
  const userAgent = req.headers['[1]'];
  res.send(userAgent);
});

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

Acontent-type

Baccept

Cuser-agent

Dauthorization

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'User-Agent' with uppercase letters (headers keys are lowercase)

Using other header names like 'authorization'

The 'user-agent' header tells the server about the client's browser or tool.

3fill in blank

hard

Fix the error in accessing the 'content-type' header from the request.

Express

app.post('/data', (req, res) => {
  const contentType = req.[1]['content-type'];
  res.send(contentType);
});

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

Aparams

Bheaders

Cbody

Dquery

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to get headers from req.body or req.params

Using wrong property names

The 'content-type' header is inside req.headers, not in body, params, or query.

4fill in blank

hard

Fill both blanks to check if the 'authorization' header exists and send a response.

Express

app.get('/auth', (req, res) => {
  if (req.[1]['[2]']) {
    res.send('Authorized');
  } else {
    res.status(401).send('Unauthorized');
  }
});

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

Aheaders

Bauthorization

Cbody

Dparams

Attempts:

3 left

💡 Hint

Common Mistakes

Checking req.body or req.params instead of req.headers

Using wrong header name spelling

Check req.headers['authorization'] to see if the client sent an authorization token.

5fill in blank

hard

Fill all three blanks to create a middleware that logs the 'host' header and calls next().

Express

function logHost(req, res, [1]) {
  console.log('Host:', req.[2]['[3]']);
  [1]();
}

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

Anext

Bheaders

Chost

Dres

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong parameter name instead of next

Accessing headers from wrong object

Forgetting to call next()

Middleware functions get next as the third argument. Use req.headers['host'] to get the host header, then call next() to continue.