What is the purpose of default value in context?

  • To provide a fallback value when a context value is not available
  • To override the context value in child components
  • To provide a default value for the context provider
  • To prevent child components from accessing the context value
The default value in context is used to provide a fallback value when a context value is not available. When a component consumes a context value, it looks for the context value in its ancestors. If no ancestor provides a value, the default value is used instead. The default value is typically used as a fallback or to provide a default value for the context.

Why fragments are better than container divs?

  • Fragments are easier to use
  • Fragments are more performant
  • Fragments are more semantic
  • Fragments are not better than container divs
Fragments are better than container divs because they are more performant. Using a container div adds an extra DOM node, which can slow down rendering and create problems with styling. Fragments, on the other hand, allow you to group elements without adding any extra nodes to the DOM.

How do you say that props are read-only?

  • By using Object.freeze()
  • By using Object.preventExtensions()
  • By using Object.seal()
  • By not modifying them directly
In React, props are read-only and should not be modified directly. Attempting to modify props directly can cause bugs and make components unpredictable. Instead, components should create and maintain their own state to manage changes to data.

What's the purpose of at symbol in the redux connect decorator?

  • It is used to reference a component's props
  • It is used to reference the Redux store's state
  • It is used to reference a component's state
The @ symbol in the Redux connect decorator is used to reference the state of the Redux store. This allows the component to access the store's state without having to pass it down as props.

How to fetch data with React Hooks?

  • Use the componentDidMount() method
  • Use the fetch() function in a useEffect() hook
  • Use the componentWillMount() method
  • Use the AJAX library
In React, you can use the useEffect() hook to fetch data from an API. Inside the useEffect() hook, you can use the fetch() function to make a request to the API and update the component state with the response data.

What is the diffing algorithm?

  • A process for comparing two React elements
  • A process for reconciling changes in the React component tree
  • A process for optimizing React component rendering
  • A process for testing React components
The diffing algorithm is the process used by React to reconcile changes in the component tree and update the DOM. The diffing algorithm compares the new tree of React elements with the previous tree and identifies the minimum set of changes needed to update the DOM. This process is also known as reconciliation and is a key part of React's performance optimizations.

Can Redux only be used with React?

  • Yes, Redux can only be used with React
  • No, Redux can be used with any JavaScript framework or library
No, Redux can be used with any JavaScript framework or library, not just React. Redux is a standalone state management library that can be used with any UI framework or library, as well as with vanilla JavaScript applications. While it is commonly used with React, it can also be used with other popular frameworks such as Angular, Vue.js, and Ember.

How to bind methods or event handlers in JSX callbacks?

  • Using arrow functions
  • Using the bind method
  • Using the new keyword
  • Using the this keyword
Methods or event handlers can be bound in JSX callbacks using arrow functions. Arrow functions inherit the context of their parent scope, which allows them to access the component's methods and state. The bind method and the this keyword can also be used to bind methods or event handlers, but arrow functions are the recommended approach.

of renderToNodeStream method?

  • To render React components on the client-side
  • To render React components on the server-side
  • To render React components in a web worker
  • To render React components in an iframe
The renderToNodeStream method is used to render React components on the server-side. It returns a Node.js stream, which allows for efficient server-side rendering of large amounts of data. This method is useful for improving the performance of server-side rendering in large applications.

What are the recommended ways for static type checking?

  • Flow
  • PropTypes library
  • TypeScript
  • TypeScript or Flow
There are several recommended ways to implement static type checking in React, including using TypeScript or Flow. TypeScript and Flow are both static type checkers that can help catch errors and bugs before they happen. The PropTypes library is another way to perform type checking, but it is less powerful than TypeScript or Flow. ESLint is a code linter that can help catch errors and enforce best practices, but it is not a type checker.