Chapter quiz · Express Foundations

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8 questions on Express Foundations. Pass 70% to clear the chapter.

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Quiz

Express Foundations — Chapter Quiz

Eight questions on app, routing, params, response, static, templates.

0/ 9

Question 1
1
What does const app = express() return?
AA function onlyBAn object that is both a function and a namespace of methodsCA classDAn HTTP server
The app is callable (as a request handler) and also has methods like get, post, use, listen.
Question 2
2
What's on req.params for the route app.get('/users/:id', ...)?
AAn array of stringsBAn object like { id: "42" } (string)CAn object like { id: 42 } (number)DThe raw URL
Path params are always strings. Coerce them yourself when you need numbers.
Question 3
3
express.json() is mounted by default.
TTrueFFalse
You must mount app.use(express.json()) to parse JSON bodies. Without it, req.body is undefined.
Question 4
4
Why prefer res.json(...) over res.send(...)?
AIt is fasterBExplicit intent — clearly sends JSON with the right Content-TypeCres.send is deprecatedDNo reason
res.send is more permissive (text, buffers, JSON). res.json is explicit and always sets Content-Type: application/json.
Question 5
5
Which is the right place to mount express.static?
AAfter all routesBAnywhere — order does not matterCEarly, before catch-all routes/404 handlersDNever, use a CDN
Mount express.static early. Otherwise other routes match first and your assets become 404s.
Question 6
6
Set the "type" field in package.json to ___ to enable ESM in .js files.
"type": "module" makes .js files ESM. Without it (or with "commonjs"), .js is CommonJS.
Question 7
7
In Express 5, what does :param? mean in a route?
AA required path parameterBAn optional path parameterCA regex patternDA wildcard
:param? is the optional-parameter syntax. The route matches with or without the segment.
Question 8
8
Which req fields ship with Express out of the box?
Select all that apply.
Areq.paramsBreq.queryCreq.bodyDreq.methodEreq.user
params, query, method are always available. body only after express.json() or similar. req.user is yours — set by your auth middleware.