React Hooks Custom Hooks

Question 1

What naming convention must all custom hooks follow?

Accepted Answer

They must start with 'use'

Answer

Custom hooks must start with 'use' so React's linter can enforce the Rules of Hooks for them.

Question 2

What is the main benefit of extracting logic into a custom hook?

Accepted Answer

Reusing stateful logic across multiple components without duplicating code

Answer

Custom hooks let you extract and share stateful logic (state, effects, subscriptions) across components cleanly.

Question 3

Can two components using the same custom hook share state?

Accepted Answer

No, each component gets its own isolated state instance

Answer

Each component that calls a custom hook gets its own isolated copy of the hook's state and effects.

Question 4

Which of the following can a custom hook contain?

Accepted Answer

Any combination of built-in hooks and logic

Answer

A custom hook is just a JavaScript function that can call any built-in or custom hooks internally.

Question 5

Where can a custom hook be called from?

Accepted Answer

Inside function components or other custom hooks

Answer

Hooks (including custom ones) can only be called at the top level of function components or other hooks.

React Practice Test