QuizApi - Challenge Your React Skills: Test Your Knowledge of Concepts & Best Practices with This Quick Quiz

Question 1

Correct Answers: 1/4

What is the correct command to create a new React project?

npm create-react-app myReactApp

npx create-react-app myReactApp

npm create-react-app

npx create-react-app

Question 2

Correct Answers: 1/4

What is the key difference between React.js functional components and class components regarding state management?

Functional components can only have local state, while class components can have both local and global state.

Functional components can only be used for presentation purposes, while class components are required for stateful logic.

Functional components do not have state, while class components can have state.

Functional components use useState hook for state management, while class components use this.state.

Question 3

Correct Answers: 1/4

What is the key difference between React's useEffect and useLayoutEffect hooks?

useLayoutEffect is only for mobile devices, while useEffect is for desktop browsers

useLayoutEffect runs synchronously after DOM mutations, while useEffect runs asynchronously after render

useLayoutEffect and useEffect are just aliases of each other with no functional difference

useLayoutEffect can only be used with class components, while useEffect is for functional components

Question 4

Correct Answers: 1/4

What happens when you call setState with identical state values in React?

The component will throw an error for redundant updates

React will always re-render the component regardless of the values

The state will be reset to its initial value

React will skip the re-render if the new state is identical to the previous state (using Object.is comparison)

Question 5

Correct Answers: 1/4

What is the primary purpose of React.memo()?

To cache the results of expensive calculations

To create a memoized version of a string or number

To store global state in a React application

To prevent functional components from re-rendering unless props change

Question 6

Correct Answers: 1/4

What is the key difference between controlled and uncontrolled components in React?

Controlled components are faster than uncontrolled components

Controlled components are managed by React state, while uncontrolled components maintain their own internal state

Uncontrolled components are deprecated in modern React

Controlled components only work with class components

Question 7

Correct Answers: 1/4

What is the purpose of the key prop when rendering lists in React?

It helps React identify which items have changed, been added, or been removed

It's used purely for styling purposes

It's used to sort the list items automatically

It's required for all React components, not just lists

Question 8

Correct Answers: 1/4

What is the primary difference between props and state in React?

Props can be changed while state is read-only

Props are internal while state is external

There is no difference between props and state

Props are read-only and passed from parent, while state is internal and can be updated by the component

Question 9

Correct Answers: 1/4

What is the purpose of React's StrictMode component?

It improves performance in production builds

It enforces type checking in React applications

It prevents runtime errors in production

It highlights potential problems in development mode

Question 10

Correct Answers: 1/4

Which hook would you use to persist a value between re-renders without causing a re-render itself?

useRef

useState

useCallback

useMemo

Question 1

What is the correct command to create a new React project?

Question 2

What is the key difference between React.js functional components and class components regarding state management?

Question 3

What is the key difference between React's useEffect and useLayoutEffect hooks?

Question 4

What happens when you call setState with identical state values in React?

Question 5

What is the primary purpose of React.memo()?

Question 6

What is the key difference between controlled and uncontrolled components in React?

Question 7

What is the purpose of the key prop when rendering lists in React?

Question 8

What is the primary difference between props and state in React?

Question 9

What is the purpose of React's StrictMode component?

Question 10

Which hook would you use to persist a value between re-renders without causing a re-render itself?

Finish Quiz