QUIZ ON : react - MISCELLANEOUS

MISCELLANEOUS

00:00:00

Question No# : 01 out of 50

What is the purpose of React's "memo" function?

A. It is used to memoize function components for performance optimization

B. It is used to handle form validation in React components

C. It is used to create reusable custom hooks

D. It is used to define the structure and layout of a React component

Question No# : 02 out of 50

What is a React component?

A. A function that returns JSX

B. A class that extends the React.Component class

C. Both a function and a class can be React components

D. None of the above

Question No# : 03 out of 50

What is the purpose of React's "useLayoutEffect" hook?

A. To handle asynchronous operations and data fetching in React components

B. To manage state in functional components

C. To perform side effects in a synchronous manner before the component is painted

D. To create reusable custom hooks

Question No# : 04 out of 50

Which of the following command is used to install create-react-app?

A. npm install -f create-react-app

B. npm install -g create-react-app

C. npm install create-react-app

D. install -g create-react-app

Question No# : 05 out of 50

What is the purpose of React's "Suspense" component?

A. To handle errors and fallback UI in React applications

B. To provide a way to lazy-load components and data in React applications

C. To handle form validation in React applications

D. None of the above

Question No# : 06 out of 50

Which of the following terms commonly described react applications?

A. Imerative

B. Integrated

C. Declarative

D. closed

Question No# : 07 out of 50

What is the purpose of React's "useContext" hook?

A. To handle form submissions in React components

B. To manage state in functional components

C. To handle navigation in React applications

D. To provide access to the context value in functional components

Question No# : 08 out of 50

What is the recommended way to fetch data from an API in React?

A. Using the fetch API provided by the browser

B. Using third-party libraries like Axios or Fetch

C. Using the built-in "fetch" method provided by React

D. All of the above

Question No# : 09 out of 50

How many numbers of elements a valid react component can return?

A. 2

B. 1

C. 4

D. 5

Question No# : 10 out of 50

What is the purpose of the "useReducer" hook in React?

A. To handle asynchronous operations and data fetching

B. To manage complex state and state transitions in functional components

C. To create reusable custom hooks

D. None of the above

Question No# : 11 out of 50

In which of the following directory React.js components are saved?

A. Inside the vendor/components/

B. Inside the vendor/

C. Inside the js/components/

D. Inside the external/components/

Question No# : 12 out of 50

In React, what is the purpose of the "forwardRef" function?

A. In React, what is the purpose of the "forwardRef" function?

B. It is used to forward props to child components

C. It is used to forward a ref to a child component

D. It is used to define the structure and layout of a React component

Question No# : 13 out of 50

Arbitrary inputs of components in React are called

A. Keys

B. Props

C. Elements

D. Ref

Question No# : 14 out of 50

What is the default port where web pack-server runs?

A. 8080

B. 6060

C. 3000

D. 3030

Question No# : 15 out of 50

What is the significance of React's "virtual DOM"?

A. It is a way to optimize rendering performance in React applications

B. It is a mechanism to handle errors and fallback UI in React applications

C. It is a technique to render React components outside of their parent component's DOM hierarchy

D. It is a representation of the actual DOM in memory, allowing efficient updates and rendering

Question No# : 16 out of 50

What is the purpose of state in React?

A. To store and manage data within a component

B. To define the structure of a React component

C. To handle user interactions in a component

D. To style the components

Question No# : 17 out of 50

What is the purpose of React's "PropTypes" library?

A. It is used to define the structure and layout of a React component

B. It is used to handle form validation in React components

C. It is used to specify the types of props that a component should receive

D. It is used to manage the state of a component

Question No# : 18 out of 50

In React, what is the purpose of the "forwardRef" function?

A. To create higher-order components (HOCs) that forward props to child components

B. To create reusable custom hooks

C. To forward the ref from a parent component to a child component

D. None of the above

Question No# : 19 out of 50

What is the purpose of keys in React lists?

A. To uniquely identify elements in a list

B. To define the layout and styling of list items

C. To handle event listeners on list items

D. None of the above

Question No# : 20 out of 50

What is snapshot testing used for in react?

A. It allows us to test Javascript objects

B. It helps you write applications

C. It provides clear, enduring assertions

D. None of the above

Question No# : 21 out of 50

What is the purpose of the "useContext" hook in React?

A. To manage state in functional components

B. To handle asynchronous operations and data fetching

C. To provide access to the nearest common ancestor component's context

D. None of the above

Question No# : 22 out of 50

What is React Hooks in React?

A. A way to create reusable logic in functional components

B. A replacement for class components in React

C. A mechanism to manage state and lifecycle in functional components

D. All of the above

Question No# : 23 out of 50

What is the purpose of React's "createContext" function?

A. It is used to create custom hooks in React

B. It is used to define the structure and layout of a React component

C. It is used to create a context object for sharing data across components

D. It is used to handle asynchronous operations and data fetching in React components

Question No# : 24 out of 50

How can you pass data from a parent component to a child component in React?

A. Using props

B. Using state

C. Using context

D. All of the above

Question No# : 25 out of 50

Which of the following statement is true for uncontrolled components in React.js?

A. The source of truth is a component state

B. The source of truth can be anything

C. The source of truth is DOM

D. None

Question No# : 26 out of 50

What is the purpose of the "React.Children" API in React?

A. It provides utilities for working with React children components

B. It manages the lifecycle of React components

C. It handles form validation in React applications

D. It optimizes the rendering performance of React components

Question No# : 27 out of 50

What is the use of “web pack” command in React.js?

A. It is a module bundler

B. The “webpack” command is used to transpile all the JavaScript down into one file

C. It runs React local development server

D. None of the above

Question No# : 28 out of 50

What is the purpose of React's "getDerivedStateFromProps" lifecycle method?

A. It is used to handle form submissions in React components

B. It is used to manage state in functional components

C. It is used to update the state of a component based on changes in props

D. It is used to handle user interactions in React components

Question No# : 29 out of 50

In which directory is react component saved?

A. vendor/js/components/

B. components/js

C. js/components

D. vendor/components

Question No# : 30 out of 50

How can you handle forms in React?

A. By using the controlled component pattern

B. By using the uncontrolled component pattern

C. By using form libraries like Formik or React Hook Form

D. All of the above

Question No# : 31 out of 50

Which of the following option is correct in the case of the Babel?

A. Babel is a Transpolar

B. Babel is a Compiler

C. All of above

D. None of above

Question No# : 32 out of 50

What is the purpose of the React Developer Tools extension?

A. It allows developers to inspect the component hierarchy and state in a React application

B. It provides a code editor specifically designed for writing React components

C. It enables real-time collaboration among multiple developers working on a React project

D. It automatically generates documentation for React components

Question No# : 33 out of 50

We can update the state in React.js by calling to setState() method. These calls are__________

A. Asynchronous in nature

B. Synchronous in nature

C. Are asynchronous but can be made synchronous when required

D. None of the these

Question No# : 34 out of 50

Which of the following is not a valid hook in React?

A. useState

B. useEffect

C. useData

D. useContext

Question No# : 35 out of 50

What is the purpose of React's "Fragment" component?

A. It is used to wrap multiple components within a single parent component

B. It is used to conditionally render components based on certain conditionsIt is used to create reusable UI components in React

C. It is used to create reusable UI components in React

D. It is used to render multiple elements without adding extra nodes to the DOM

Question No# : 36 out of 50

What is the purpose of the "React.memo" function in React?

A. It is used to memoize function components for performance optimization

B. It is used to create custom hooks in React

C. It is used to manage state in class components

D. None of the above

Question No# : 37 out of 50

In React, what is the purpose of the "shouldComponentUpdate" method?

A. To determine if a component should re-render or not

B. To handle asynchronous actions and side effects

C. To define the initial state of a component

D. To handle user interactions in a component

Question No# : 38 out of 50

What is a state in React?

A. External storage of the component

B. A permanent storage

C. Internal storage of the component

D. None of the above

Question No# : 39 out of 50

What is the purpose of the "React.memo" higher-order component (HOC)?

A. It is used to memoize function components for performance optimization

B. It is used to create reusable custom hooks in React

C. It is used to manage state in class components

D. It is used to handle asynchronous operations and data fetching

Question No# : 40 out of 50

In React, what is the purpose of the "defaultProps" property?

A. It specifies the default values for props in a component

B. It sets the initial state of a component

C. It defines the default styling for a component

D. It determines the default behavior of a component's lifecycle methods

Question No# : 41 out of 50

Which of the following method is not a part of ReactDOM?

A. ReactDOM.destroy()

B. ReactDOM.hydrate()

C. ReactDOM.createPortal()

D. ReactDOM.findDOMNode()

Question No# : 42 out of 50

What is used to handle code-splitting?

A. React.lazy

B. React.memo

C. React.fallback

D. React.split

Question No# : 43 out of 50

What is the purpose of React's "key" prop when rendering a list of elements?

A. It determines the order in which the list items are rendered

B. It ensures unique styling for each list item

C. It improves the performance of rendering the list

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

Question No# : 44 out of 50

What is the significance of the "key" prop in React when rendering a list of elements?

A. It ensures unique styling for each list item

B. It determines the order in which the list items are rendered

C. It improves the performance of rendering the list

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

Question No# : 45 out of 50

When is useReducer used over useState in React component?

A. When we want to replace redux

B. When we want to break our production app

C. When we want to improve performance

D. none of the above

Question No# : 46 out of 50

What are the two ways to handle data in React?

A. Services & Components

B. State & Component

C. State & Props

D. State & Services

Question No# : 47 out of 50

How can you handle errors in React components?

A. By using the "try-catch" block in the component's render method

B. By using the "componentDidCatch" lifecycle method to catch and handle errors

C. By using global error handling provided by the browser

D. None of the above

Question No# : 48 out of 50

What is the concept of React portals?

A. It is a way to create reusable UI components in React

B. It is a mechanism to optimize rendering performance in React

C. It is a way to render React components outside of their parent component's DOM hierarchy

D. None of the above

Question No# : 49 out of 50

What is the purpose of the "useEffect" hook in React?

A. To handle form submissions in React components

B. To manage the lifecycle of functional components

C. To handle user interactions in React components

D. To create reusable logic in React components

Question No# : 50 out of 50

Which method in a React Component should you override to stop the component from updating?

A. willComponentUpdate

B. shouldComponentUpdate

C. componentDidUpdate

D. componentDidMount