[Solved] What is wrong with this Angular observable subscription code?this.data$ = this.http.get('/api/data');this.data$.subscribe(data => { this.data = data;});this.data$.subscribe(data => { console.... | Angular

Angular - RxJS and Observables Fundamentals

What is wrong with this Angular observable subscription code?

this.data$ = this.http.get('/api/data');
this.data$.subscribe(data => {
  this.data = data;
});
this.data$.subscribe(data => {
  console.log(data);
});

AThe subscribe method is misspelled.

BMultiple subscriptions can cause repeated HTTP calls.

CObservables cannot be assigned to variables.

DThe HTTP get method does not return an observable.

Step-by-Step Solution

Solution:

Step 1: Analyze multiple subscriptions to the same observable
Each subscription to an HTTP observable triggers a new HTTP request, causing repeated calls.
Step 2: Identify the problem in the code
Here, this.data$ is subscribed twice, so two HTTP requests are sent, which is inefficient and often unwanted.
Final Answer:
Multiple subscriptions can cause repeated HTTP calls. -> Option B
Quick Check:
Multiple subscriptions = repeated HTTP calls [OK]

Quick Trick: Avoid multiple subscriptions to HTTP observables [OK]

Common Mistakes:

MISTAKES

Thinking subscribe is misspelled
Believing observables can't be variables
Assuming HTTP get returns non-observable

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What is wrong with this Angular observable subscription code?

Step 1: Analyze multiple subscriptions to the same observable

Step 2: Identify the problem in the code

Final Answer:

Quick Check:

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