React Review and Assessment 3

Question 1

What problem does the useCallback hook solve?

Accepted Answer

Memoizing a function so it keeps the same reference between renders

Answer

useCallback returns a memoized callback that only changes when its dependencies change.

Question 2

How is data passed from a parent to a child component?

Accepted Answer

Through props

Answer

Parents pass data to children via props.

Question 3

What does the Context API help avoid?

Accepted Answer

Prop drilling through many intermediate components

Answer

Context lets you share values deeply without passing props through every level.

Question 4

Which hook would you use to access a DOM element directly?

Accepted Answer

useRef

Answer

useRef holds a mutable reference, commonly attached to DOM nodes.

Question 5

What is the correct way to update state based on the previous state?

Accepted Answer

Pass a function to the setter: setCount(prev => prev + 1)

Answer

Using the updater function form guarantees you read the latest state value.

React Practice Test