React State Management 3

Question 1

What problem does the Context API primarily solve?

Accepted Answer

Prop drilling through many component levels

Answer

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

Question 2

Which component makes a context value available to its descendants?

Accepted Answer

Context.Provider

Answer

The Provider supplies the value to all components beneath it.

Question 3

What is the modern hook for reading a context value in a function component?

Accepted Answer

useContext

Answer

useContext reads the current value of a given context.

Question 4

When a context value changes, what happens to components that consume it?

Accepted Answer

All consuming components re-render

Answer

Every consumer of the context re-renders when its value changes.

Question 5

Why can putting an object literal directly in a Provider's value prop hurt performance?

Accepted Answer

A new object reference each render forces consumers to re-render

Answer

A fresh object reference on every render makes consumers re-render unnecessarily.

React Practice Test