res.download for file downloads in Express - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does res.download() do in Express?

res.download() sends a file to the client and prompts them to download it. It sets the right headers so the browser knows it's a file to save.

beginner

What are the main parameters of res.download()?

The main parameters are: path (file path), filename (optional new name for the file), and callback (optional function called after download or on error).

intermediate

How does res.download() differ from res.sendFile()?

res.download() forces the browser to download the file, while res.sendFile() just displays or opens the file in the browser if possible.

intermediate

What happens if the file path in res.download() is incorrect or file is missing?

The callback function receives an error, and Express can handle it (like sending a 404 response). Without a callback, Express sends a 404 response.

beginner

Why is it important to use absolute paths with res.download()?

Absolute paths avoid confusion about where the file is located, preventing errors and security issues by ensuring the correct file is sent.

What does res.download() do in Express?

A Sends a file and prompts the user to download it

B Sends JSON data to the client

C Renders a view template

D Redirects the client to another URL

res.download() sends a file and triggers the browser's download prompt.

Which parameter is NOT part of res.download()?

A File path

B HTTP status code

C Callback function

D Filename for download

res.download() does not take an HTTP status code parameter.

If you want the browser to open a file instead of downloading, which method should you use?

A res.download()

B res.redirect()

C res.sendFile()

D res.json()

res.sendFile() sends the file to display or open in the browser.

What should you do to handle errors when using res.download()?

A Set a timeout for the download

B Ignore errors, Express handles them automatically

C Use try-catch around <code>res.download()</code>

D Use a callback function to catch errors

Passing a callback lets you handle errors like missing files gracefully.

Why prefer absolute paths with res.download()?

A To avoid file path confusion and security issues

B To improve download speed

C To change the file name automatically

D To compress the file before sending

Absolute paths ensure the correct file is sent and reduce security risks.

Explain how to use res.download() to send a file for download in Express.

Think about what parameters you pass and what happens in the browser.

Describe the difference between res.download() and res.sendFile() in Express.

Consider how the browser treats the file in each case.