Quiz | Croma Campus

What is a pure component in React?

A component with no side effects
A component that only re-renders when its props change
A component that always re-renders
A component that fetches data

Mark for review

Which of the following methods is called after the component is rendered in React?

componentWillMount()
omponentDidMount()
componentDidUpdate()
componentWillReceiveProps

Mark for review

In React, what does the virtual DOM do?

It directly manipulates the real DOM
It optimizes CSS styling
It provides a way to manipulate browser cookies
It reconciles the changes made to the UI

Mark for review

Who developed React.js?

Google
Apple
Facebook
Microsoft

Mark for review

What is prop drilling?

Passing props to multiple components
Updating state in child components
Updating props in parent components
Passing state down multiple levels

Mark for review

What is a component in React?

A function that returns JSX
A class that fetches data
A library for routing
A method for state management

Mark for review

Which of the following statements about React Hooks is true?

They only work with class components
They allow you to use state and other React features without writing a class
They are used to define component lifecycle methods
They are deprecated in the latest version of React

Mark for review

How do you handle side effects in a functional component?

Using useEffect
Using useState
Using useContext
Using useReducer

Mark for review

How do you create a context in React?

Using React.createContext
Using useContext
Using useEffect
Using useReducer

Mark for review

What is the virtual DOM in React?

A real DOM that is virtualized
A JavaScript object
An API for backend calls
A type of database

Mark for review

How do you handle errors in React components?

Using componentDidCatch
Using useEffect
Using useState
Using render

Mark for review

What is the purpose of the 'defaultProps' property in React?

To define default values for props
To specify the default state of a component
To set the default event handlers
To define default CSS styles

Mark for review

What is the purpose of the 'useMemo' Hook in React?

To memoize expensive calculations
To update the component's state
To handle component errors
To perform side effects in function components

Mark for review

What is the purpose of the 'useDebugValue' Hook in React?

To handle component errors
To debug custom Hooks
To update the component's state
To perform side effects in function components

Mark for review

Which of the following is NOT a way to handle events in React?

Inline event handlers
Event delegation
Event listeners
Synthetic events

Mark for review

Which of the following is NOT a built-in Hook in React?

useCallback
useMemo
useState
useComponent

Mark for review

What is the purpose of StrictMode in React?

To highlight potential problems
To manage state
To fetch data
To handle errors

Mark for review

Which method is called when a component is first added to the DOM?

componentDidMount()
componentWillMount()
componentWillUpdate()
componentDidUpdate

Mark for review

How do you handle forms with controlled components?

Using value and onChange props
Using defaultValue prop
Using setState
Using useEffect

Mark for review

What is the purpose of keys in React?

To identify elements uniquely
To set state
To define props
To handle events

Mark for review

What is the purpose of ReactDOM?

To define components
To manage state
To render React components to the DOM
To create context

Mark for review

What is React.js?

A programming language
A JavaScript library for building user interfaces
A database management system
An operating systemAnswer

Mark for review

What is the purpose of middleware in Redux?

To handle asynchronous actions
To handle synchronous actions
To fetch data
To manage state

Mark for review

How do you handle forms in React?

Using Redux
Using refs
Using state
Using Context API

Mark for review

How do you create a reference to a DOM element in React?

Using createRef
Using useState
Using useEffect
Using useReducer

Mark for review

What is the purpose of state in React?

To store props
To store component metadata
To manage component input
To manage component data that may change

Mark for review

What is the purpose of useMemo hook?

To memoize functions
To memoize values
To handle side effects
To fetch data

Mark for review

How can you prevent a component from rendering in React?

By setting the 'visible' attribute to false
By returning null from the render method
By using the 'shouldComponentUpdate' method
By removing the component from the component tree

Mark for review

What is the purpose of the 'getDerivedStateFromProps' method in React?

To update the component's state based on props changes
To initialize the component's state
To perform side effects after rendering
To handle component errors

Mark for review

How can you optimize performance in React?

By using pure components
By minimizing the use of inline styles
By avoiding unnecessary re-renders
All of the above

Mark for review

Online Exam Quiz

Online

Did you like this Question

Get a 1:1 Mentorship call with our Career Advisor