Mutations & Forms — Chapter Quiz

Question 1

1

What does 'use server' at the top of a file mean?

AEvery export is a Server Action that can be called from a client component or formBThe file only runs on EdgeCForces the file to be a Server ComponentDDisables hydration for the route

'use server' marks every export as a Server Action — callable directly from client components and form action props.

Question 2

2

How do you invoke a Server Action from a form without JavaScript on the page?

A<form onSubmit={action}>B<form action={action}>C<form actionUrl={action}>DServer Actions require JS

<form action={serverAction}> works even without JS — Next submits the form to the action via a normal HTTP POST.

Question 3

3

What does useActionState give you?

AThe previous return value of the action plus a wrapped form-action that updates it on submitBA pending boolean onlyCA way to cancel an in-flight actionDA redux store

useActionState(action, initial) returns [state, formAction]. State holds whatever the action returns; formAction is the wrapped action you pass to <form action>.

Question 4

4

useFormStatus must be called from a component nested inside the <form>.

TTrueFFalse

useFormStatus reads the surrounding form's status. The form itself does not have access to its own status — only its descendants do.

Question 5

5

Why is Zod a common partner for Server Actions?

AIt replaces FormDataBIt validates user input on the server, returning typed data or structured errorsCIt encrypts cookiesDIt is required by Next.js

Server Actions accept untrusted input — Zod (or any schema library) gives you a single place to validate and infer types.

Question 6

6

After a successful mutation, which call updates the cache for the affected page?

Arouter.refresh()BrevalidatePath('/posts')Cfetch('/posts') againDNothing — Next refreshes automatically

revalidatePath (and revalidateTag) is the canonical way to invalidate the server caches after an action.

Question 7

7

The hook for optimistic updates is useO_________.

useOptimistic(state, reducer) lets you show a predicted state immediately while the action runs in the background.

Question 8

8

Which of these can a Server Action do?

Select all that apply.

ARead and write cookiesBQuery the database directlyCUse browser APIs like localStorageDCall revalidateTag to invalidate cache

Server Actions run on the server — they can touch the DB, cookies, and cache APIs. Browser-only globals like localStorage are not available.

Test what you learned.