What is the main purpose of constructor?

  • To initialize the component's state and bind methods to the component
  • To define the component's markup and styling
  • To render the component's children
  • To handle events and update the component's state
The main purpose of the constructor in a React component is to initialize the component's state and bind methods to the component. The constructor is called before the component is mounted and can be used to set the initial state of the component or to bind methods to the component.

How to use font-awesome icons in React?

  • Use the Font Awesome component library for React
  • Import the Font Awesome CSS file and use the class names
  • Use the React Native vector icons library
  • There is no way to use Font Awesome icons in React
To use Font Awesome icons in React, you can use the Font Awesome component library for React. This library provides a set of pre-built components for rendering Font Awesome icons, which you can use in your React applications. Alternatively, you can import the Font Awesome CSS file and use the class names directly in your components.

Can you describe the componentDidCatch lifecycle method signature?

  • componentDidCatch(error: Error, errorInfo: object)
  • componentDidCatch(error: string, errorInfo: object)
  • componentDidCatch(error: Error, errorInfo: string)
  • componentDidCatch(error: string, errorInfo: string)
The componentDidCatch lifecycle method is called whenever an error is thrown in a component's child tree. The method has a signature of componentDidCatch(error: Error, errorInfo: object). The error parameter is the actual error object that was thrown, while the errorInfo parameter is an object that contains additional information about the error, such as the component stack trace.

What is the benefit of strict mode?

  • It enforces stricter type checking for props and state
  • It improves the performance of React applications
  • It helps identify potential problems in code early on
  • It enables advanced debugging features in React Developer Tools
The strict mode feature in React is used to identify potential problems in code early on in the development process. It activates additional checks and warnings for common mistakes and unsafe operations, such as using deprecated lifecycle methods or modifying props directly. This can help prevent bugs and improve the overall quality of the code.

Why React uses className over class attribute?

  • To avoid naming conflicts with JavaScript class keyword
  • To follow HTML5 standard
  • To improve performance
  • To make the markup more concise
React uses className instead of class attribute to avoid naming conflicts with the JavaScript class keyword. Using className also makes it easier to use CSS modules and other tools that work with class names.

How to access current locale with React Intl

  • Use the "formatMessage" function with the "locale" option
  • Use the "intl" object provided by the "injectIntl" higher-order component
  • Use the "Intl" object provided by the browser
  • Use the "navigator.language" property
In React Intl, you can access the current locale by using the "intl" object provided by the "injectIntl" higher-order component. This object contains information about the current language, locale, and formatting options, and can be used to format text and data in the correct format. For example: const { locale } = this.props.intl;.

What is children prop?

  • A prop that contains the child components of a component
  • A prop that contains the parent component of a component
  • A prop that is passed to the constructor() method of a component
  • A prop that is used to update a component's state
The children prop is a special prop in React that contains the child components of a component. It allows components to render their child components directly, without having to pass them down through props. The children prop can be used with any component, including functional components.

Why are Redux state functions called reducers?

  • Because they reduce the state of the application
  • Because they reduce the complexity of the application
  • Because they reduce the size of the application
  • Because they reduce the coupling between components
Redux state functions are called reducers because they take the current state of the application and an action as input, and return a new state as output. This process of reducing the state of the application is the core principle of Redux.

Does the statics object work with ES6 classes in React?

  • Yes, the statics object works with ES6 classes
  • No, the statics object only works with React.createClass()
Yes, the statics object works with ES6 classes in React. The statics object is used to define static properties for a React component, such as defaultProps or propTypes. In ES6 classes, you can define static properties using the static keyword, like so: 'static defaultProps = {...}'. This is equivalent to using the statics object in React.createClass().

What is the use of react-dom package?

  • To create React components
  • To handle routing in React components
  • To manage state in React components
  • To render React components to the DOM
The react-dom package is used to render React components to the DOM. The react-dom package provides several methods for rendering components, including the render method and the hydrate method.