Cache-Control header directives in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the effect of this Cache-Control header?

Given the HTTP response header:

Cache-Control: no-store

What will the browser do with the response?

A The browser will cache the response but revalidate it on every request.

B The browser will cache the response and serve it without revalidation until it expires.

C The browser will store the response only if it is marked as public.

D The browser will not store the response in any cache and will fetch it fresh every time.

💡 Hint

Think about what 'no-store' means for caching behavior.

The 'no-store' directive tells browsers and caches not to store any part of the response. This means the response is always fetched fresh and never saved.

❓ Predict Output

intermediate

What is the output of this Cache-Control header?

Consider this HTTP response header:

Cache-Control: max-age=3600, must-revalidate

What does this mean for the cached response?

A The response can be served from cache for 3600 seconds, but after that it must be revalidated before use.

B The response must be revalidated with the server before every use, ignoring max-age.

C The response can be served from cache for up to 3600 seconds without checking with the server.

D The response is cached indefinitely and never revalidated.

💡 Hint

Consider how max-age and must-revalidate work together.

max-age=3600 means the response is fresh for 3600 seconds. must-revalidate means after that time, the cache must check with the server before using the cached response.

🔧 Debug

advanced

Identify the error in this Cache-Control header

A developer wrote this Cache-Control header:

Cache-Control: max-age=abc, public

What error will this cause?

A The header will cache the response for 0 seconds.

B The header will cause a server error and the response will not be sent.

C The header will be ignored because max-age value is invalid (not a number).

D The header will cache the response indefinitely because max-age is ignored.

💡 Hint

Check the format required for max-age values.

max-age must be a non-negative integer. Using 'abc' is invalid, so the header is ignored or treated as if max-age is not set.

🧠 Conceptual

advanced

Which Cache-Control directive allows shared caches but prevents private caches?

Which Cache-Control directive below allows caching by shared caches (like proxies)?

A private

B public

C no-cache

D no-store

💡 Hint

Think about which directive marks a response as cacheable by any cache.

'public' means the response can be cached by any cache, including shared caches. 'private' restricts caching to private caches only.

❓ Predict Output

expert

What is the number of directives in this Cache-Control header?

Count the number of valid directives in this Cache-Control header:

Cache-Control: no-cache, max-age=600, private, must-revalidate, proxy-revalidate

A 5

B 4

C 3

D 6

💡 Hint

Count each directive separated by commas.

The header has five directives: no-cache, max-age=600, private, must-revalidate, and proxy-revalidate.