MEAN Express.js Middleware and Routing

Question 1

What is the correct order of arguments in an Express.js error-handling middleware function?

Accepted Answer

(err, req, res, next)

Answer

(req, res, err, next)

Answer

(req, err, res, next)

Answer

(err, res, req, next)

Question 2

Which Express.js method is used to define a route that handles all HTTP methods?

Accepted Answer

app.all()

Answer

app.any()

Answer

app.use()

Answer

app.route()

Question 3

What does `express.json()` middleware do in an Express application?

Accepted Answer

Parses incoming requests with JSON payloads and populates req.body

Answer

Serializes response objects to JSON automatically

Answer

Validates JSON schema of request bodies

Answer

Compresses JSON responses

Question 4

How do you define a URL parameter in an Express route?

Accepted Answer

app.get('/users/:id', handler)

Answer

app.get('/users/{id}', handler)

Answer

app.get('/users/[id]', handler)

Answer

app.get('/users/<id>', handler)

Question 5

What is the purpose of calling `next()` in Express middleware?

Accepted Answer

Passes control to the next matching middleware or route handler

Answer

Sends the response to the client

Answer

Moves to the next HTTP request

Answer

Skips remaining middleware in the chain

Question 6

Which Express.js method creates a modular route handler that can be mounted at a path?

Accepted Answer

express.Router()

Answer

express.route()

Answer

app.module()

Answer

app.group()