Node.js Express.js & REST APIs 2

Question 1

Which Express method registers middleware that runs for every incoming request regardless of path?

Accepted Answer

app.use(fn)

Answer

app.use(fn) without a path mounts middleware at '/' which matches every request.

Question 2

What does the Express Router class primarily help you accomplish?

Accepted Answer

Modularize route definitions into mini-apps

Answer

express.Router() creates a mini-app that groups related routes and middleware for modularity.

Question 3

In a REST API, which HTTP status code should be returned when a resource is successfully created?

Accepted Answer

201 Created

Answer

201 Created signals that the request succeeded and a new resource was created.

Question 4

What is the purpose of calling next(err) inside an Express middleware?

Accepted Answer

Passes control to the next error-handling middleware

Answer

Passing an argument to next() triggers Express's error-handling pipeline, skipping regular middleware.

Question 5

Which of the following correctly accesses a URL query parameter in Express?

Accepted Answer

req.query.q

Answer

req.query contains the parsed query string key-value pairs from the URL.

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