Angular Web Framework HTTP Client & API Integration 3

Question 1

What is the role of HttpParams in Angular HTTP requests?

Accepted Answer

Building an immutable, encodable set of URL query string parameters

Answer

Storing server-side session variables between requests

Answer

Defining named route parameters in the Angular router

Answer

Configuring request timeout and retry intervals

Question 2

How do you make an HTTP request that bypasses all registered HttpInterceptors?

Accepted Answer

Inject HttpBackend directly and use it to dispatch the request

Answer

Pass skipInterceptors: true in the request options

Answer

Use the native fetch() API instead of HttpClient

Answer

Set interceptors: [] on the HttpClientModule import

Question 3

Which RxJS operator should be used to cancel a pending HTTP request when a new trigger value arrives, preventing stale responses?

Accepted Answer

switchMap

Answer

mergeMap

Answer

concatMap

Answer

exhaustMap

Question 4

Which combination of HttpClient options is required to receive HTTP upload progress events?

Accepted Answer

reportProgress: true combined with observe: 'events', then filter for UploadProgress

Answer

observe: 'progress' only

Answer

responseType: 'stream' and observe: 'body'

Answer

progressMode: true and observe: 'response'

Question 5

What must an HttpInterceptor call to forward the request to the next interceptor or to the actual HTTP backend?

Accepted Answer

next.handle(req)

Answer

http.send(req)

Answer

interceptor.next(req)

Answer

this.forward(req)

Question 6

What happens when HttpClient.get() is called but its returned Observable is never subscribed to?

Accepted Answer

No HTTP request is sent because observables are cold and lazy

Answer

The HTTP request is sent immediately upon calling get()

Answer

Angular throws a runtime error about unsubscribed observables

Answer

The request is queued until the next change detection cycle

Question 7

How can you share a single HTTP request result among multiple subscribers without triggering duplicate network calls?

Accepted Answer

Pipe the observable through shareReplay(1)

Answer

Use HttpClient.share() built-in method

Answer

Subscribe manually and feed results into a BehaviorSubject

Answer

Enable response caching in the HttpClientModule import options