res.redirect for redirections in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to redirect the user to '/home'.

Express

app.get('/start', (req, res) => {
  res.[1]('/home');
});

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

Asend

Brender

Credirect

Djson

Attempts:

3 left

💡 Hint

Common Mistakes

Using res.send instead of res.redirect

Using res.render which is for templates

The res.redirect() method sends a redirect response to the client, telling it to go to a different URL.

2fill in blank

medium

Complete the code to redirect with a 301 status code to '/new-page'.

Express

app.get('/old-page', (req, res) => {
  res.status(301).[1]('/new-page');
});

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

Aredirect

Bsend

Cjson

Drender

Attempts:

3 left

💡 Hint

Common Mistakes

Using res.send instead of res.redirect

Not setting the status code before redirect

Use res.redirect() after setting the status code to send a permanent redirect (301).

3fill in blank

hard

Fix the error in the code to properly redirect to '/dashboard'.

Express

app.get('/login', (req, res) => {
  res.redirect [1] '/dashboard';
});

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

A()

B[]

C{}

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting parentheses when calling res.redirect

Using square or curly brackets instead of parentheses

The redirect method requires parentheses around the URL string.

4fill in blank

hard

Fill both blanks to redirect with a 302 status code to '/profile'.

Express

app.get('/user', (req, res) => {
  res.[1]([2], '/profile');
});

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

Aredirect

Bsend

C302

D301

Attempts:

3 left

💡 Hint

Common Mistakes

Using res.send instead of res.redirect

Using wrong status code like 301 for temporary redirect

Use res.redirect(statusCode, url) to redirect with a specific status code like 302.

5fill in blank

hard

Fill all three blanks to redirect to '/logout' only if user is logged in.

Express

app.get('/exit', (req, res) => {
  if (req.user) {
    res.[1]([2], [3]);
  } else {
    res.send('Not logged in');
  }
});

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

Aredirect

B302

C'/logout'

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Using res.send instead of res.redirect

Forgetting quotes around the URL string

Using wrong status code

Use res.redirect(302, '/logout') to redirect logged-in users to logout.

Practice

1. What does res.redirect('/home') do in an Express app?

easy

A. Sends a JSON response with '/home' data

B. Stops the server from running

C. Sends the user to the '/home' URL automatically

D. Logs '/home' to the console

Solution

1. Step 1: Understand res.redirect purpose

   The res.redirect method sends an HTTP redirect response to the client, telling the browser to go to a new URL.

2. Step 2: Analyze the argument '/home'

   Passing '/home' means the user will be redirected to the '/home' path on the same server.

3. Final Answer:

   Sends the user to the '/home' URL automatically -> Option C

4. Quick Check:

   res.redirect('/home') = Redirect to '/home' [OK]

Hint: res.redirect sends user to given URL automatically [OK]

Common Mistakes:

• Thinking it sends JSON data
• Confusing redirect with stopping server
• Assuming it logs to console

2. Which is the correct syntax to redirect permanently to '/dashboard' in Express?

easy

A. res.redirect('/dashboard', 301);

B. res.redirect(301, '/dashboard');

C. res.redirectPermanent('/dashboard');

D. res.redirectPermanent(301, '/dashboard');

Solution

1. Step 1: Recall res.redirect syntax for status code

   Express uses res.redirect(statusCode, url) to specify redirect type.

2. Step 2: Identify correct order of arguments

   The status code (301) must come first, then the URL string.

3. Final Answer:

   res.redirect(301, '/dashboard'); -> Option B

4. Quick Check:

   Status code first, URL second = res.redirect(301, '/dashboard'); [OK]

Hint: Status code goes first in res.redirect(status, url) [OK]

Common Mistakes:

• Swapping arguments order
• Using non-existent res.redirectPermanent method
• Passing status code as second argument

3. What will the browser do after this Express code runs?

app.get('/old', (req, res) => {
  res.redirect('/new');
});

medium

A. Show the content of '/old' page

B. Send a JSON response with '/new' data

C. Return a 404 error

D. Redirect the browser to '/new' URL

Solution

1. Step 1: Understand route handler behavior

   The handler for '/old' calls res.redirect('/new'), which sends a redirect response.

2. Step 2: Browser reaction to redirect

   The browser receives the redirect and automatically requests the '/new' URL instead of '/old'.

3. Final Answer:

   Redirect the browser to '/new' URL -> Option D

4. Quick Check:

   res.redirect('/new') = Browser goes to '/new' [OK]

Hint: res.redirect sends browser to new URL automatically [OK]

Common Mistakes:

• Expecting original page content to show
• Thinking it returns 404 error
• Confusing redirect with JSON response

4. Find the error in this Express code snippet:

app.get('/start', (req, res) => {
  res.redirect('/end', 302);
});

medium

A. The status code should be first argument, not second

B. res.redirect cannot be used inside app.get

C. The URL must be absolute, not relative

D. 302 is not a valid redirect status code

Solution

1. Step 1: Check res.redirect argument order

   Express expects res.redirect(statusCode, url), status code first.

2. Step 2: Identify incorrect argument order

   The code uses res.redirect('/end', 302), which is reversed and causes unexpected behavior.

3. Final Answer:

   The status code should be first argument, not second -> Option A

4. Quick Check:

   Correct order: status, URL [OK]

Hint: Status code must come before URL in res.redirect [OK]

Common Mistakes:

• Swapping status and URL arguments
• Thinking res.redirect can't be used in routes
• Believing relative URLs are invalid
• Assuming 302 is invalid status

5. You want to redirect users from '/login' to '/dashboard' only if they are logged in. Which code correctly uses res.redirect to do this?

hard

A. if (req.user) { res.redirect('/dashboard'); } else { res.send('Please login'); }

B. res.redirect('/dashboard'); if (req.user) { res.send('Welcome'); }

C. res.redirect(302, '/dashboard'); res.send('Logged in');

D. if (!req.user) { res.redirect('/dashboard'); } else { res.send('Please login'); }

Solution

1. Step 1: Check login condition usage

   The code must check if req.user exists to confirm login.

2. Step 2: Redirect only if logged in

   If logged in, redirect to '/dashboard'; otherwise, send a message to login.

3. Step 3: Verify correct use of res.redirect and res.send

   if (req.user) { res.redirect('/dashboard'); } else { res.send('Please login'); } correctly calls res.redirect inside the if block and sends response otherwise, avoiding multiple responses.

4. Final Answer:

   if (req.user) { res.redirect('/dashboard'); } else { res.send('Please login'); } -> Option A

5. Quick Check:

   Redirect only when logged in = if (req.user) { res.redirect('/dashboard'); } else { res.send('Please login'); } [OK]

Hint: Redirect inside if block after login check [OK]

Common Mistakes:

• Calling res.redirect without condition
• Sending multiple responses in one request
• Redirecting when user is not logged in