Books

Learn HTML Learn CSS Learn Git Learn Javascript Learn PHP Learn python Learn Java

Exercises

HTML JavaScript Git CSS PHP

Courses Quizzes Snippets

Tools

General Tools

Password Generator
HTML Editor
HTML Encoder
Base 64
Code Diff
JSON Beautifier
CSS Beautifier
Markdown Convertor
Find the Closest Tailwind CSS Color
Phrase encrypt / decrypt
Browser Feature Detection
Number convertor

CSS Maker

CSS Maker
CSS Maker text shadow
CSS Maker Text Rotation
CSS Maker Out Line
CSS Maker RGB Shadow
CSS Maker Transform
CSS Maker Font Face

Color Tools

Color Picker
Colors CMYK
Colors HWB
Colors HSL
Color Hex
Color mixer
Color Converter
Colors RGB
Color Contrast Analyzer
Color Gradient

String Tools

String Length Calculator
MD5 Hash Generator
Sha256 Hash Generator
String Reverse
URL Encoder
URL Decoder
Base 64 Encoder
Base 64 Decoder
Extra Spaces Remover
String to Lowercase
String to Uppercase
Word Count Calculator
Empty Lines Remover
HTML Tags Remover
Binary to Hex
Hex to Binary
Rot13 Transform on a String
String to Binary
Duplicate Lines Remover

Books
How To

React Basics

1/25 The lifecycle methods are mainly used for ___.
- keeping track of event history
- enhancing components
- freeing up resources
- none of the above
2/25 ___ can be done while multiple elements need to be returned from a component.
- Abstraction
- Packing
- Insulation
- Wrapping
3/25 Which of the following methods in a React Component should be overridden to stop the component from updating?
- willComponentUpdate
- shouldComponentUpdate
- componentDidUpdate
- componentDidMount
4/25 What is used to pass data to a component from outside?
- setState
- render with arguments
- PropTypes
- props
5/25 What will happen if you call setState() inside render() method?
- Repetitive output appears on the screen
- Duplicate key error
- Stack overflow error
- Nothing happens
6/25 What is ReactJS?
- Server side Framework
- User-interface framework
- Library for building interaction interfaces
7/25 What are the two ways that data gets handled in React?
- state & props
- services & components
8/25 What is the purpose of the 'key' prop in a React list?
- To identify each element uniquely
- For styling elements
- To enhance performance
- To trigger events
9/25 What does 'PureComponent' do in React?
- Manages pure functions
- Prevents re-rendering if props and state have not changed
- Cleans up the component
- Enhances component performance
10/25 How do you create a ref in a class component in React?
- React.createRef()
- React.ref()
- this.ref.create()
- new Ref()
11/25 What is the default port where a create-react-app project runs?
- 3000
- 8080
- 5000
- 8000
12/25 What does the 'useMemo' hook do in React?
- It memorizes a computed value
- It saves memory usage
- It recalls previously rendered components
- It memorizes the component state
13/25 What is a Fragment in React?
- A part of the component state
- A tool for memoization
- A component that can return multiple elements
- A higher-order component
14/25 How do you pass a prop named 'data' to a component named 'MyComponent'?
- <MyComponent data={this.props.data} />
- <MyComponent props={data} />
- <MyComponent>{data}</MyComponent>
- <MyComponent data='data' />
15/25 Which of these is a correct way to handle events in React?
- <button onClick={this.handleClick}>Click me</button>
- <button onClick='handleClick()'>Click me</button>
- <button onClick={handleClick()}>Click me</button>
- <button handle='onClick'>Click me</button>
16/25 What does 'props.children' represent in a React component?
- The state of the parent component
- The children passed to the component
- A type of React child component
- The props of the child components
17/25 What does 'React.Fragment' do?
- It groups a list of children without adding extra nodes to the DOM
- It is a method to optimize performance
- It is used to fragment a component into smaller components
- It is a way to render components asynchronously
18/25 What is the significance of keys in React lists?
- They are used for styling purposes
- They help React identify which items have changed, are added, or are removed
- They represent the unique ID of each element
- They increase the performance of list rendering
19/25 What does 'lifting state up' mean in React?
- Moving state to a common ancestor of components that need it
- Increasing the performance of the state updates
- Automatically handling state changes in child components
- Transferring state to a higher-order component
20/25 Which method is the right choice to fetch data in a useEffect hook?
- componentDidMount
- useFetch
- fetch API
- getData()
- useDataFetching
21/25 What does 'prop drilling' refer to in React?
- Passing props to deep child components
- Setting default prop values
- Validating prop types
- Updating props from child components
22/25 In React, what is a 'higher-order component' (HOC)?
- A component with higher z-index
- A component that returns another component
- A stateful component
- A component that renders HTML elements
23/25 How do you share state between two components that are not parent-child in React?
- Using global variables
- Using the Context API
- Passing props through intermediate components
- Using a state management library like Redux
24/25 How do you handle form submissions in React?
- Using an onSubmit event handler
- With a dedicated form management library
- By directly submitting to the server
- React does not support form submissions
25/25 What is the use of the 'useEffect' hook in React?
- To manage component state
- To perform side effects in functional components
- For rendering optimizations
- To create reusable components
To get the result of the quiz, please provide your email address (optional)..

It seems you haven't answered any questions yet. Please provide your answers to proceed.

Quizzes
Snippets
Our Books
- Learn HTML
- Learn CSS
- Learn Git
- Learn Javascript
- Learn PHP
- Learn python
- Learn Java
- Exercises
- HTML
- JavaScript
- Git
- CSS
- PHP
Our Tools

About Us
Privacy Policy for W3Docs

Follow Us

Company © W3docs. All rights reserved.