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Graded Quiz :D Post published. View post Dismiss this notice. Add titleeveloping Back-End Apps with Node.js and Express (Cloud Application Development Foundations Specialization) Answers 2025

1. What best describes the network operations Node.js makes?

❌ Non-blocked operations return in sync with added time
Non-blocked operations return immediately without added processing time on the server
❌ Applications block every network operation
❌ Blocked operations return immediately

Explanation:
Node.js uses non-blocking I/O, meaning operations return instantly while work continues in the background.


2. What does the immediate result of http.request() state?

A request is in progress.
❌ Message will be sent successfully
❌ Callback executed successfully
❌ Response will be sent successfully

Explanation:
http.request() returns a ClientRequest object, indicating the request has been initiated.


3. Which parameter is optional in an HTTP request?

❌ Resource variable
❌ Event variable
❌ Location function
Callback function parameter

Explanation:
Node’s HTTP request API allows you to omit the callback. You can attach events instead.


4. What object is passed as the first parameter in a Node.js callback?

❌ Destination
❌ Location
❌ Identity
Error

Explanation:
Node uses the error-first callback pattern:
callback(error, result).


5. What do you pass to indicate a successful callback return?

❌ 404 status code
Null object
❌ Empty string
❌ Error

Explanation:
In Node.js, success is indicated by passing null as the first argument of the callback.


6. Which function calls resultCallback to return results?

❌ step()
❌ aggregate_context()
❌ http.request()
result()

Explanation:
Based on the pattern described, result() triggers resultCallback.


7. Why can inversion of control be an issue when using callbacks?

❌ Requires nested callbacks
❌ Uses promises
Third-party code gains control, making errors hard to track
❌ Used for sequential behavior

Explanation:
Callback inversion means you “hand over control” to external code, risking hidden errors.


8. JSON’s relationship with Node.js

❌ Metadata file
Standard representation of native JavaScript objects
❌ Common data model folder
❌ JSON_SET

Explanation:
JSON is essentially JavaScript object syntax, making it natural for Node.js APS.


9. When an error occurs, the promise is in which state?

Rejected
❌ Pending
❌ Resolved
❌ Aborted

Explanation:
A failed promise enters the rejected state.


10. What method does a promise use after completion?

then
❌ or
❌ if
❌ else

Explanation:
promise.then() handles resolved values; .catch() handles rejected ones.


🧾 SUMMARY TABLE

Q# Correct Answer
1 Non-blocked ops return immediately
2 A request is in progress
3 Callback function parameter
4 Error
5 Null object
6 result()
7 Third-party control makes errors hard to identify
8 Standard representation of JS objects
9 Rejected
10 then