[Solved] Consider the following Angular RxJS code:import { of, combineLatest } from 'rxjs';... combineLatest([obs1, obs2]).subscribe(console.log);What will be the output logged to the console? | Angular

Angular - RxJS Operators

Consider the following Angular RxJS code:

import { of, combineLatest } from 'rxjs';

const obs1 = of(3, 4);
const obs2 = of('X', 'Y');

combineLatest([obs1, obs2]).subscribe(console.log);

What will be the output logged to the console?

A[4, 'Y']

B[3, 'X'] and then [4, 'Y']

C[3, 'Y'] and then [4, 'X']

D[3, 'X'] only

Step-by-Step Solution

Solution:

Step 1: Understand of emissions
of(3,4) emits 3 then 4 synchronously, same for of('X','Y').
Step 2: Behavior of combineLatest
combineLatest waits for each observable to emit at least once, then emits the latest values whenever any observable emits.
Step 3: Synchronous emissions
Since both observables emit synchronously, the last emitted values are 4 and 'Y'. combineLatest will emit only once with these latest values.
Final Answer:
The console logs [4, 'Y'] once, matching [4, 'Y'].
Quick Check:
Synchronous of emissions cause combineLatest to emit only the last combined values. [OK]

Quick Trick: Synchronous observables emit last combined values once [OK]

Common Mistakes:

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