Top 10 React.js useContext() Interview Questions

What is the useContext() hook in React?
It’s a React hook that lets you access context values from a React context without nesting.

How do you use useContext() in a functional component?
Import useContext, pass the context object, and assign the returned value to a variable.

What problem does useContext() solve?
It eliminates prop drilling by providing a way to share data across the component tree.

How do you create a context for useContext()?
Use React.createContext() to create a context object, then wrap components with its Provider.

Can useContext() replace Redux or other state management libraries?
It can for simple state sharing, but complex state management may still require Redux.

What happens if useContext() is used without a Provider?
It returns the default value defined in createContext() or undefined if none is set.

How does useContext() differ from useReducer()?
useContext() accesses shared context data, while useReducer() manages local component state.

Can you use multiple contexts with useContext()?
Yes, call useContext() multiple times with different context objects.

What are the performance implications of useContext()?
Rerenders occur in consuming components when the context value changes.

When should you avoid using useContext()?
Avoid for frequently changing values to prevent unnecessary rerenders in large component trees.