The ________ library in React is popular for creating responsive and interactive charts.
- React Graph
- React Charts
- Recharts
- Chart.js
The "Recharts" library is popular in the React community for creating responsive and interactive charts. It offers a simple and declarative API for building charts within React applications. While other chart libraries can be used, Recharts is known for its ease of use and customization options. The other options are not as closely associated with React charting.
In a project, you're required to fetch data from multiple REST endpoints simultaneously and display it only when all the data is available. Which Axios method would be most suitable for this?
- Axios.all()
- Axios.concurrent()
- Axios.parallel()
- Axios.series()
To fetch data from multiple REST endpoints simultaneously and wait for all the data to be available before proceeding, you should use 'Axios.all()' to make multiple requests concurrently. 'Axios.parallel()' and 'Axios.concurrent()' are not standard Axios methods, and 'Axios.series()' would make requests sequentially, not concurrently.
In the context of React, why can immutability lead to more efficient rendering?
- It causes more memory leaks.
- It increases the component's complexity.
- It reduces the need for virtual DOM diffing.
- It slows down the rendering process.
Immutability in React can lead to more efficient rendering because it reduces the need for virtual DOM diffing. When the state or props of a component are immutable, React can easily compare the previous and current values to determine what parts of the DOM need to be updated. This optimization can significantly improve the performance of React applications by minimizing unnecessary re-renders.
What is the primary benefit of using TypeScript with React?
- Enhanced code readability and maintainability.
- Faster rendering of React components.
- Improved integration with third-party libraries.
- Automatic code deployment to production servers.
The primary benefit of using TypeScript with React is enhanced code readability and maintainability. TypeScript provides static typing, which helps catch errors at compile time and provides better IntelliSense support. This leads to more robust and maintainable code. While the other options might be desirable in different contexts, they are not the primary benefit of using TypeScript with React.
Which of the following describes React Native?
- A hybrid mobile app development framework.
- A native mobile app development platform.
- A popular JavaScript framework for web apps.
- A programming language for server-side scripting.
React Native is a hybrid mobile app development framework. It allows developers to build mobile applications for multiple platforms (e.g., iOS and Android) using a single codebase in JavaScript and React. While React Native uses native components, it is distinct from native development platforms.
The primary library to handle immutable data structures, which can be beneficial for React's performance, is ______.
- Immutable.js
- Lodash-Immutable
- MobX
- Redux
The primary library for handling immutable data structures in the context of React's performance is "Immutable.js." Immutable data structures help prevent unexpected side effects, making it easier to reason about your application's state. This library can be highly beneficial when used in conjunction with React, improving application performance and maintainability.
In React, the common pattern to provide data to many components efficiently, which can be used with Websockets, is called ________.
- Component Propagation
- HOC (Higher Order Component)
- Redux
- State Sharing
In React, the common pattern to provide data to many components efficiently, including those using Websockets, is called Redux. Redux is a state management library that allows you to store and manage application state in a centralized store. It facilitates efficient data sharing among components, making it suitable for scenarios where real-time data from Websockets needs to be distributed across many parts of an application.
In React Transition Group, what prop is used to define the duration of an exit animation?
- transitionDuration
- animationDuration
- exitDuration
- duration
In React Transition Group, the prop used to define the duration of an exit animation is exitDuration. This prop allows you to control how long it takes for a component to animate out of the view when it's being removed. The other options (transitionDuration, animationDuration, and duration) are not specific to exit animations in React Transition Group.
How can you ensure a component does not re-render unnecessarily when consuming a context?
- Using memoization techniques like React.memo().
- Implementing context with useState.
- Wrapping the component with React.StrictMode.
- Increasing the component's complexity.
To prevent unnecessary re-renders when consuming context, you can use memoization techniques like React.memo(). This higher-order component wraps the component and only re-renders it when its props or context values change. It's a performance optimization technique to avoid unnecessary re-renders, especially when the component depends on context values. The other options are not related to preventing re-renders due to context consumption.
In a MobX-powered e-commerce application, you want to ensure that the cart total is automatically updated whenever an item is added or its quantity is changed. Which approach would you use to achieve this efficient update?
- Actions
- Computed Properties
- Observables
- Reactions
To achieve an efficient update of the cart total in response to changes in items or their quantities, you would use Reactions in MobX. Reactions are triggered automatically when observable data they depend on changes. In this case, a reaction can recalculate the cart total whenever the cart items or their quantities change, ensuring an automatic and efficient update.