Node.js Technology & Digital Applications 4

Question 1

Which environment variable is conventionally used to set the Node.js execution environment (e.g., development, production)?

Accepted Answer

NODE_ENV

Answer

`NODE_ENV` is the widely adopted convention used by frameworks like Express to toggle behavior between development and production.

Question 2

What does the `--save-dev` flag do when running `npm install`?

Accepted Answer

Adds the package to `devDependencies` in package.json

Answer

`--save-dev` (or `-D`) adds the package under `devDependencies`, indicating it's only needed during development and not in production.

Question 3

In the context of Node.js, what is a 'middleware' function in Express?

Accepted Answer

A function with access to req, res, and next that sits in the request-response cycle

Answer

Middleware functions receive `(req, res, next)` and can execute code, modify the request/response, or pass control to the next middleware via `next()`.

Question 4

What is the purpose of the `package-lock.json` file?

Accepted Answer

Records the exact resolved versions of all dependencies for reproducible installs

Answer

`package-lock.json` captures the exact dependency tree so that `npm ci` can reproduce identical installs across environments.

Question 5

Which Node.js API would you use to schedule a function to execute repeatedly every 2 seconds?

Accepted Answer

setInterval(fn, 2000)

Answer

`setInterval(fn, 2000)` executes `fn` repeatedly at approximately 2-second intervals until cleared with `clearInterval()`.

Node.js Practice Test

Node.js Practice Test

Node.js Technology & Digital Applications 4