QUIZ ON : react - MISCELLANEOUS

MISCELLANEOUS

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Question No# : 01 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# : 02 out of 50

What is the purpose of the "React.Fragment" component in React?

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

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

C. It is used as a wrapper to render multiple elements without adding extra nodes to the DOM

D. None of the above

Question No# : 03 out of 50

Which of following is used to pass data to a component from outside?

A. PropTypes

B. setState

C. render with arguments

D. props

Question No# : 04 out of 50

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

A. To update the state of a component

B. To define the initial state of a component

C. To handle user interactions in a component

D. To render the component's UI

Question No# : 05 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# : 06 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# : 07 out of 50

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

A. Controlled components rely on state for managing their data, while uncontrolled components do not.

B. Controlled components allow user input to directly update the component's state, while uncontrolled components do not.

C. Controlled components are created using classes, while uncontrolled components are created using functions.

D. There is no difference; the terms are used interchangeably.

Question No# : 08 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# : 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

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# : 11 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# : 12 out of 50

What is React context used for?

A. To pass data to deeply nested components without explicit prop drilling

B. To manage the global state of a React application

C. To enable communication between sibling components

D. All of the above

Question No# : 13 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# : 14 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# : 15 out of 50

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

A. 8080

B. 6060

C. 3000

D. 3030

Question No# : 16 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# : 17 out of 50

What is the purpose of the "render" method in React?

A. To define the initial state of a component

B. To render the component's UI based on its current state and props

C. To handle user interactions and update the component's state

D. To define the lifecycle methods of a component

Question No# : 18 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# : 19 out of 50

What is the functionality of a “webpack” command?

A. Runs react local development server

B. transfer files all the JavaScript down into one file

C. a module blunder

D. none of the above

Question No# : 20 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# : 21 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# : 22 out of 50

Which of the following terms commonly described react applications?

A. Imerative

B. Integrated

C. Declarative

D. closed

Question No# : 23 out of 50

What is the virtual DOM in React?

A. An alternative implementation of the DOM provided by React

B. A lightweight version of the DOM used for testing purposes

C. A concept used to optimize rendering performance in React

D. None of the above

Question No# : 24 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# : 25 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# : 26 out of 50

What is JSX in React?

A. JavaScript XML

B. Java syntax extension

C. A templating language

D. None of the above

Question No# : 27 out of 50

What is used to handle code-splitting?

A. React.lazy

B. React.memo

C. React.fallback

D. React.split

Question No# : 28 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# : 29 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# : 30 out of 50

Which of the following function is used to change the state of the React.js component?

A. this.setChangeState

B. this.State{}

C. this.setState

D. None of the above

Question No# : 31 out of 50

What is the lifecycle method used for initializing state and binding event handlers in React?

A. componentDidMount

B. componentDidUpdate

C. componentWillMount

D. constructor

Question No# : 32 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# : 33 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# : 34 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# : 35 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

Question No# : 36 out of 50

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

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

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

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

D. It is used to memoize functions for performance optimization

Question No# : 37 out of 50

Which company developed ReactJS?

A. Apple

B. Facebook

C. Google

D. Twitter

Question No# : 38 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# : 39 out of 50

What is the purpose of the "React.StrictMode" component in React?

A. To enable additional debugging checks and warnings in the development mode

B. To enforce strict code quality rules in React applications

C. To ensure compatibility with older versions of React

D. To optimize rendering performance in React applications

Question No# : 40 out of 50

What is the purpose of React's "StrictMode"?

A. To enforce strict code quality rules in React applications

B. To enable additional debugging checks and warnings in the development mode

C. To ensure compatibility with older versions of React

D. None of the above

Question No# : 41 out of 50

What is true for the keys given to a list of elements in React?

A. Unique in the DOM.

B. Unique among the siblings only.

C. Do not require to be unique.

D. None of the above.

Question No# : 42 out of 50

In react, the key should be?

A. Unique among his siblings only

B. Unique in the DOM

C. Does not requires to be unique

D. all of the above

Question No# : 43 out of 50

What is the purpose of React hooks like "useMemo" and "useCallback"?

A. To optimize the performance of functional components by memoizing values and functions

B. To manage the state of functional components

C. To handle side effects in functional components

D. None of the above

Question No# : 44 out of 50

What is the purpose of the "React.Fragment" shorthand syntax in React?

A. It is used to create a new React component

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

C. It is used to define the initial state of a component

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

Question No# : 45 out of 50

Why is useLayoutEffect used?

A. To complete the update

B. To optimize for all devices

C. To change the layout of the screen

D. when you need the browser to paint before the effectors

Question No# : 46 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# : 47 out of 50

What is the concept of "lifting state up" in React?

A. Moving the state from a child component to its parent component

B. Moving the state from a parent component to its child component

C. Extracting the state into a separate utility function

D. Sharing the state between multiple unrelated components

Question No# : 48 out of 50

In relation to React js component lifecycle, which statement is true

A. Only function component can have life cycle

B. Only class components can have life cycle

C. Both type of components can have life cycle

D. None of above

Question No# : 49 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# : 50 out of 50

What is the purpose of React's "setState" method when called with a function as an argument?

A. It is used to define the initial state of a component

B. It is used to handle user interactions in a component

C. It is used to update the state of a component based on the previous state

D. It is used to render the component's UI