Context and State Management

Question 1

What is React Context?

Accepted Answer

React Context is a feature that lets you pass data through the component tree without manually passing props at every level. It is useful for global data such as the current user, theme, or language preference.

Question 2

What does useContext do?

Accepted Answer

useContext is a hook that lets a component read a value from a React context without wrapping it in a Consumer component. It accepts a context object and returns the current context value from the nearest matching provider above it in the tree.

Question 3

When should you avoid using Context?

Accepted Answer

Context should be avoided when the data changes frequently, because every consumer re-renders when the context value changes. For frequently changing shared state, a dedicated state management library or local state is often a better choice.

Question 4

What is the Context API compared to Redux?

Accepted Answer

The Context API is a built-in React feature for passing data through the tree without prop drilling. Redux is a full state management library with middleware, devtools, and strict update rules. Context is simpler; Redux scales better for complex state.

Question 5

What is Redux?

Accepted Answer

Redux is a predictable state management library often used with React. It stores application state in a single store, updates it through pure reducer functions in response to dispatched actions, and enforces a unidirectional data flow.

Question 6

What are the three principles of Redux?

Accepted Answer

Single source of truth, meaning state lives in one store; state is read-only and can only change by dispatching actions; and changes are made with pure reducer functions that take the previous state and an action and return a new state.

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