MEAN Express.js Middleware and Routing 2

Question 1

What does the `express.static()` middleware do?

Accepted Answer

Serves static files like HTML, CSS, and images from a directory

Answer

Generates static HTML from templates

Answer

Caches dynamic responses as static files

Answer

Validates static file MIME types

Question 2

How do you set the HTTP status code of a response in Express.js?

Accepted Answer

res.status(404).send('Not Found')

Answer

res.setStatus(404)

Answer

res.code(404)

Answer

response.status = 404

Question 3

What is CORS and how is it commonly handled in an Express API?

Accepted Answer

Cross-Origin Resource Sharing, handled with the cors npm middleware package

Answer

Client-Origin Request System, handled with helmet middleware

Answer

Cross-Origin Route Sharing, handled in app.all()

Answer

Content Origin Restriction Scheme, handled in package.json

Question 4

Which Express.js method sends a JSON response with the correct Content-Type header?

Accepted Answer

res.json()

Answer

res.send({})

Answer

res.write(JSON.stringify())

Answer

res.end(JSON.stringify())

Question 5

What does `app.use()` do in Express.js when used without a path argument?

Accepted Answer

Mounts middleware that runs for every incoming request

Answer

Defines a catch-all route for undefined paths

Answer

Sets global app configuration

Answer

Registers a default route handler

Question 6

How do you access query string parameters in Express.js (e.g., /search?q=mean)?

Accepted Answer

req.query.q

Answer

req.params.q

Answer

req.body.q

Answer

req.search.q