Which popular React framework is primarily used for Server-Side Rendering?
- Angular
- Next.js
- Redux
- Vue.js
Next.js is a popular React framework primarily used for Server-Side Rendering (SSR). It simplifies the process of building SSR-enabled React applications, providing features like automatic code splitting and routing. While Redux is a state management library for React, Angular is a different framework, and Vue.js is another JavaScript framework, they are not primarily used for SSR in the same way Next.js is.
How do CSS-in-JS libraries like styled-components handle server-side rendering (SSR) for styling?
- They do not support SSR.
- They generate inline styles on the server-side.
- They rely on external CSS files for SSR.
- They dynamically load styles on the client-side after rendering.
CSS-in-JS libraries like styled-components generate inline styles on the server-side, which are then included in the HTML response. This approach ensures that styles are applied during the initial render on the server, enhancing performance and SEO. The other options do not accurately describe how CSS-in-JS libraries handle SSR.
In React, ______ and Suspense are used together to implement lazy loading of components.
- React.lazy()
- useEffect() and Fetch
- useState() and Axios
- useMemo() and Promises
In React, React.lazy() and Suspense are used together to implement lazy loading of components. React.lazy() allows you to dynamically load a component when it's needed, and Suspense is used to handle loading states. The other options are not directly related to lazy loading components.
Which hook would be best suited to manage the global state of an application?
- useContext
- useEffect
- useRef
- useState
The hook best suited to manage the global state of an application is useContext. useContext provides a way to share data (state) between components without prop drilling. It is often used in combination with useReducer or useState to manage global application state. While the other hooks have their use cases, useContext is specifically designed for global state management in React applications.
The Context API provides a way to pass data through the component tree without having to pass props down manually at every level using the ________ and ________ mechanism.
- Provider and Consumer
- State and Props
- Render Props and HOC
- Redux and MobX
The Context API in React provides the Provider and Consumer components, which allow data to be passed through the component tree without the need to manually pass props down at every level. This mechanism simplifies state management in complex React applications. While the other options are related to React state management, they do not specifically describe the Context API mechanism.
The method that provides detailed information about the error and the component stack where it happened is called ________.
- renderError
- componentErrorBoundary
- errorStack
- componentStack
The method that provides detailed information about the error and the component stack where it happened is called componentStack. This information is invaluable when debugging errors in React applications as it helps developers pinpoint the exact location and context of the error. The other options (renderError, componentErrorBoundary, and errorStack) are not standard methods in React for providing this specific information.
You notice that a React component handling real-time chat messages re-renders excessively, even when no new messages are received. What could be a probable cause, and how would you address it?
- The component is not using PureComponent or memoization.
- There is a memory leak in the component.
- The chat messages are not being received correctly.
- The server is not sending updates efficiently.
Excessive re-renders in a React component can often be caused by not using PureComponent or memoization. PureComponent and memoization techniques help prevent unnecessary re-renders when no new data has arrived, optimizing performance. Addressing this issue involves implementing PureComponent or memoization in the component to reduce unnecessary rendering. The other options do not directly address the probable cause.
When using React.lazy(), it's recommended to handle network failures using a component that wraps around ________.
- ErrorBoundary
- ErrorWrapper
- FallbackComponent
- Suspense
When using React's React.lazy() for code splitting and dynamic imports, it's recommended to handle network failures by wrapping your lazy-loaded components with an ErrorBoundary. The ErrorBoundary component catches any errors that occur during the loading of the lazy component and allows you to display a fallback UI or handle the error gracefully.
To create a cross-platform mobile application using React's principles, developers often turn to ________.
- Angular
- React Native
- Vue.js
- Xamarin
To create a cross-platform mobile application using React's principles, developers often turn to React Native. React Native is a framework that allows developers to build mobile applications for iOS and Android using React's component-based approach. Angular, Vue.js, and Xamarin are alternatives to React Native for cross-platform mobile development, but they are not specifically built on React's principles.
In MobX, what is the best practice for modifying observable state?
- Directly modifying the state without any restrictions.
- Modifying the state only within actions or reactions.
- Only allowing modifications in the constructor of the class.
- Using third-party libraries for state management.
The best practice in MobX is to modify observable state only within actions or reactions. This ensures that state changes are tracked correctly and that MobX can optimize reactivity. Directly modifying the state without restrictions can lead to unpredictable behavior. The other options are not considered best practices in MobX.