Angular Web Framework HTTP Client & API Integration 2

Question 1

How do you add custom HTTP headers to an HttpClient request?

Accepted Answer

By passing an HttpHeaders object via the headers option

Answer

By modifying the global fetch API before the call

Answer

By setting document.headers before the request

Answer

By using a map() pipe operator on the response

Question 2

What is the purpose of HttpClientTestingModule in Angular unit tests?

Accepted Answer

To provide a mock HTTP backend so requests can be flushed and asserted

Answer

To speed up HTTP calls in the test environment

Answer

To enable HTTPS during local development

Answer

To automatically retry failed requests in tests

Question 3

How do you cancel an in-flight HTTP request in Angular?

Accepted Answer

Unsubscribe from the Observable returned by HttpClient

Answer

Call HttpClient.cancel() with the request reference

Answer

Set timeout: 0 in the request options object

Answer

Call request.abort() on the XHR object

Question 4

What does setting withCredentials: true in an HttpClient request do?

Accepted Answer

Includes cookies and authorization headers in cross-origin requests

Answer

Automatically adds a CSRF token to every request

Answer

Enables HTTP/2 multiplexing for the request

Answer

Forces the request to use HTTPS regardless of the URL

Question 5

How do you configure HttpClient to return the raw response body as a plain string instead of parsed JSON?

Accepted Answer

responseType: 'text'

Answer

observe: 'text'

Answer

contentType: 'text/plain'

Answer

type: 'string'

Question 6

Which RxJS operator automatically re-issues an HTTP request up to 3 times when it fails?

Accepted Answer

retry(3)

Answer

repeat(3)

Answer

retryWhen(() => 3)

Answer

catchError(() => retry())

Question 7

How should you send a JavaScript object as a JSON body in an HttpClient.post() request?

Accepted Answer

Pass the plain object as the body argument; Angular serializes it automatically

Answer

Always call JSON.stringify() and manually set Content-Type header

Answer

Wrap it in FormData before passing it

Answer

Use HttpParams to encode the object as form fields