RxJS MCQs with answers Page - 3

Here, you will find a collection of MCQ questions on RxJS. Go through these questions to enhance your preparation for upcoming examinations and interviews.

To check the correct answer, simply click the View Answer button provided for each question.

Have your own questions to contribute? Click the button below to share your MCQs with others!

+ Add Question

F

Fox Root • 195 Points
Mover

Q. What does the reduce() operator do in RxJS?

  • (A) Filters values
  • (B) Accumulates values and emits a single result on completion
  • (C) Creates multiple Observables
  • (D) Stops subscription

F

Fox Root • 195 Points
Mover

Q. Which operator ignores the first n emissions?

  • (A) take()
  • (B) skip()
  • (C) drop()
  • (D) ignore()

F

Fox Root • 195 Points
Mover

Q. Which operator emits values until another Observable emits?

  • (A) takeUntil()
  • (B) takeWhile()
  • (C) repeat()
  • (D) timeout()

F

Fox Root • 195 Points
Mover

Q. What does combineLatest() do?

  • (A) Emits values only from the first Observable
  • (B) Combines the latest values from multiple Observables
  • (C) Stops Observables
  • (D) Delays emissions

F

Fox Root • 195 Points
Mover

Q. Which operator emits only the first value?

  • (A) first()
  • (B) single()
  • (C) elementAt()
  • (D) takeLast()

F

Fox Root • 195 Points
Mover

Q. Which operator repeats an Observable after completion?

  • (A) repeat()
  • (B) retry()
  • (C) share()
  • (D) publish()

F

Fox Root • 195 Points
Mover

Q. Which operator retries the source Observable when an error occurs?

  • (A) retry()
  • (B) repeat()
  • (C) recover()
  • (D) catchError()

F

Fox Root • 195 Points
Mover

Q. What is the purpose of share() operator?

  • (A) Shares a single subscription among multiple subscribers
  • (B) Duplicates data
  • (C) Stops Observables
  • (D) Stores values in database

F

Fox Root • 195 Points
Mover

Q. Which operator emits pairs of previous and current values?

  • (A) pairwise()
  • (B) zip()
  • (C) scan()
  • (D) concat()

F

Fox Root • 195 Points
Mover

Q. Which operator buffers values and emits them as an array periodically?

  • (A) bufferTime()
  • (B) collect()
  • (C) groupBy()
  • (D) mergeMap()

Add MCQ in this Category

If you want to share an MCQ question in this category, it's a great idea! It will be helpful for many other students using this website.

Share Your MCQ

Browse Categories

Click on category to learn MCQs of that category.