Conditional middleware execution in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add middleware that runs only for POST requests.

Express

app.use((req, res, next) => {
  if (req.method === '[1]') {
    console.log('POST request detected');
  }
  next();
});

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

AGET

BDELETE

CPUT

DPOST

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'GET' instead of 'POST' will run middleware on GET requests.

Forgetting to call next() will block the request.

The middleware checks if the request method is 'POST' to run the code only for POST requests.

2fill in blank

medium

Complete the code to apply middleware only on routes starting with '/admin'.

Express

app.use('[1]', (req, res, next) => {
  console.log('Admin route accessed');
  next();
});

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

A/user

B/api

C/admin

D/public

Attempts:

3 left

💡 Hint

Common Mistakes

Using '/user' will not affect admin routes.

Leaving the path empty applies middleware to all routes.

Middleware with path '/admin' runs only on routes that start with '/admin'.

3fill in blank

hard

Fix the error in the middleware to run only if query parameter 'debug' equals 'true'.

Express

app.use((req, res, next) => {
  if (req.query.debug [1] 'true') {
    console.log('Debug mode active');
  }
  next();
});

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

A===

B==

C=

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' causes assignment error.

Using '==' may cause type coercion issues.

Use '===' for strict equality check in JavaScript to compare query parameter to string 'true'.

4fill in blank

hard

Fill both blanks to create middleware that runs only for PUT requests on '/update' path.

Express

app.[1]('/update', (req, res, next) => {
  if (req.method === '[2]') {
    console.log('Update request received');
  }
  next();
});

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

Aput

Bpost

CGET

DPUT

Attempts:

3 left

💡 Hint

Common Mistakes

Using app.post() will not handle PUT requests.

Checking req.method === 'GET' will never be true for PUT requests.

Use app.put() to handle PUT requests on '/update' path and check method 'PUT' inside middleware.

5fill in blank

hard

Fill all three blanks to create middleware that runs only if the user is authenticated and the request method is DELETE on '/remove' path.

Express

app.[1]('/remove', (req, res, next) => {
  if (req.user && req.method === '[2]') {
    console.log('Authenticated DELETE request');
    [3]();
  } else {
    res.status(403).send('Forbidden');
  }
});

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

Adelete

BDELETE

Cnext

Dpost

Attempts:

3 left

💡 Hint

Common Mistakes

Using app.post() instead of app.delete().

Not calling next() causes request to hang.

Checking req.method === 'delete' (lowercase) fails.

Use app.delete() for DELETE requests on '/remove'. Check req.method === 'DELETE'. Call next() to continue middleware chain.