MEAN Express.js Middleware and Routing 4

Question 1

What does calling `next('route')` do inside an Express route handler?

Accepted Answer

Skips remaining handlers in the current route and passes control to the next matching route

Answer

`next('route')` skips any remaining handlers registered on the current route and jumps to the next route that matches the request.

Question 2

Which Express method binds middleware that runs for every HTTP verb on a specific path?

Accepted Answer

app.all()

Answer

`app.all()` matches all HTTP methods for a given path, while `app.use()` also matches sub-paths and is intended for mounting middleware.

Question 3

In Express, what is the correct signature for an error-handling middleware function?

Accepted Answer

(err, req, res, next)

Answer

Express identifies error-handling middleware by its four-parameter signature `(err, req, res, next)`, which must be declared exactly this way.

Question 4

What happens if an Express middleware function does not call `next()` and does not send a response?

Accepted Answer

The request hangs indefinitely

Answer

If a middleware neither calls `next()` nor ends the response, the request remains open and the client waits until a network or server timeout occurs.

Question 5

Which of the following correctly defines a parameterized route in Express that captures an integer-like segment named `id`?

Accepted Answer

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

Answer

Express supports optional regex constraints on route parameters using the syntax `:param(regex)`, so `/:id(\d+)` restricts `id` to digits.

MEAN - Stack Development Practice Test