Top React Interview Quiz: Key Concepts & Output-Based Questions

Clicking the button increments the count by 1.

Clicking the button increments the count by 2.

Clicking the button does nothing.

The code throws an error.

An unordered list with three items: 1: React, 2: JavaScript, 3: CSS.

The code throws an error because key should be unique.

The code outputs an unordered list but without item indices.

The code outputs only the last item in the list.

useMemo and useCallback.

useState and useReducer.

useEffect and useLayoutEffect.

useContext and useRef.

10

15

20

It results in an infinite loop.

It prevents rendering of the application in production mode.

It activates additional checks and warnings in development mode.

It improves performance in both development and production.

It enables the usage of experimental features.

Button displays 0 initially and increments by 1 on each click.

Button displays 1 initially and increments by 2 on each click.

Button displays 0 initially but does not increment.

The code throws an error.

Renders a placeholder for components.

Groups multiple elements without adding extra DOM nodes.

Improves performance by caching components.

Ensures components re-render on state changes.

An error because multiple root elements are not allowed.

Two div elements rendered inside a single parent.

Two div elements rendered without a parent.

Two div elements rendered inside a React.Fragment parent.

React is a full-fledged framework, while Angular is a library.

React uses a one-way data flow, and Angular uses two-way data binding.

React and Angular both rely on JSX for templating.

React requires TypeScript, while Angular does not.

An empty .

A with This will not render.

A syntax error.

The text "This will not render" displayed as a string.