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In Angular, which of these statements about Observables is true?

easy🧠 Conceptual Q2 of 15
Angular - RxJS and Observables Fundamentals
In Angular, which of these statements about Observables is true?
AObservables execute immediately without subscription.
BObservables are lazy and start emitting values only when subscribed to.
CObservables cannot be canceled once started.
DObservables always emit values synchronously.
Step-by-Step Solution
Solution:

  1. Step 1: Recall Observable execution

    Observables do not start emitting until a subscription is made, making them lazy.

  2. Step 2: Check other options

    Observables can be canceled by unsubscribing, and they can emit asynchronously.

  3. Final Answer:

    Observables are lazy and start emitting values only when subscribed to. -> Option B

  4. Quick Check:

    Observable laziness = subscription triggers [OK]
Quick Trick: Observables wait for subscription to start [OK]
Common Mistakes:
MISTAKES
  • Assuming Observables start immediately
  • Believing Observables can't be canceled
  • Thinking Observables are always synchronous

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