Express JS Express Request and Response 2

Question 1

What does res.sendFile() do in Express?

Accepted Answer

Sends a file as the HTTP response with appropriate Content-Type

Answer

res.sendFile() transfers a file at the given path as the response, automatically setting the Content-Type header.

Question 2

Which method chains status code setting and sends a response in a single line?

Accepted Answer

res.status(200).json(data)

Answer

res.status() returns the response object, allowing you to chain .json() or .send() on the same line.

Question 3

How do you set a response header in Express?

Accepted Answer

res.set('Header-Name', 'value') or res.setHeader()

Answer

res.set() (or res.header()) sets response headers, supporting both single and multiple header values.

Question 4

What does req.ip contain in an Express application?

Accepted Answer

The IP address of the remote client

Answer

req.ip contains the remote IP address of the request, or the leftmost IP from X-Forwarded-For if trust proxy is enabled.

Question 5

Which property contains the full URL path including the query string in Express?

Accepted Answer

req.originalUrl

Answer

req.originalUrl preserves the original request URL including the full path and query string, even within mounted routers.

Express JS Practice Test