[Solved] Consider this code snippet:const subject = new BehaviorSubject('start'); subject.... subject.subscribe(value => console.log('Subscriber 2:', value));What will be printed to the console? | Angular

Angular - RxJS and Observables Fundamentals

Consider this code snippet:

const subject = new BehaviorSubject('start');
subject.next('first');
subject.subscribe(value => console.log('Subscriber 1:', value));
subject.next('second');
subject.subscribe(value => console.log('Subscriber 2:', value));

What will be printed to the console?

ASubscriber 1: start Subscriber 1: first Subscriber 1: second Subscriber 2: second

BSubscriber 1: first Subscriber 1: second Subscriber 2: first Subscriber 2: second

CSubscriber 1: first Subscriber 1: second Subscriber 2: second

DSubscriber 1: start Subscriber 1: second Subscriber 2: start Subscriber 2: second

Step-by-Step Solution

Solution:

Step 1: Trace BehaviorSubject emissions
BehaviorSubject starts with 'start', then next emits 'first'. Subscriber 1 subscribes after 'first', so it receives the last value 'first' immediately, then 'second' when emitted.
Step 2: Analyze Subscriber 2 subscription
Subscriber 2 subscribes after 'second' is emitted, so it immediately receives 'second'.
Final Answer:
Subscriber 1: start
Subscriber 1: first
Subscriber 1: second
Subscriber 2: second -> Option A
Quick Check:
BehaviorSubject sends last value on subscribe [OK]

Quick Trick: BehaviorSubject sends last value immediately on subscribe [OK]

Common Mistakes:

MISTAKES

Assuming Subscriber 2 gets 'first' value
Ignoring initial 'start' emission to Subscriber 1
Ignoring immediate emission on subscription

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More Angular Quizzes

Consider this code snippet:

Step 1: Trace BehaviorSubject emissions

Step 2: Analyze Subscriber 2 subscription

Final Answer:

Quick Check:

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