React Hooks Building React App 4

Question 1

Which hook avoids passing props through many intermediate components (prop drilling)?

Accepted Answer

useContext

Answer

useContext reads a shared context value without threading props through every level.

Question 2

To create a context in a React app, which API do you call?

Accepted Answer

React.createContext()

Answer

createContext returns a Context object with a Provider and a default value.

Question 3

Which hook is preferred for complex state logic with multiple sub-values?

Accepted Answer

useReducer

Answer

useReducer centralizes complex state transitions via a reducer function.

Question 4

What does a useReducer dispatch function do?

Accepted Answer

Sends an action to the reducer to compute new state

Answer

Dispatch sends an action object that the reducer uses to return the next state.

Question 5

Which hook caches an expensive computed value between renders?

Accepted Answer

useMemo

Answer

useMemo memoizes a computed value and recalculates only when dependencies change.

React Practice Test