ReactJS Training in Surat

Server-Side Rendering is a technique where React components are rendered on the server and the complete HTML is sent to the browser. This improves SEO, reduces initial load time, and improves performance, especially for users on slow networks. Frameworks like Next.js are widely used for implementing SSR in React applications.

Hydration is the process by which React attaches event listeners and activates the JavaScript logic on top of the server-rendered HTML. It ensures the page becomes interactive after the static HTML is loaded. This is a critical part of SSR, as it connects the server-rendered UI with client-side logic.

useCallback is a React hook that memoizes a function, returning the same instance unless its dependencies change. It’s particularly useful when passing callbacks to child components to prevent unnecessary re-renders. It improves performance in components that rely on functions that don’t change frequently.

useMemo is a hook that memoizes the result of an expensive computation and recalculates it only when dependencies change. It helps optimize performance by avoiding redundant calculations during each render cycle. It’s ideal for scenarios involving large data processing or complex logic.

The children prop allows components to receive and render nested elements or other components between their opening and closing tags. It provides flexibility in component composition and is commonly used for layout components, wrappers, modals, and reusable UI elements.

React Portals allow rendering a component’s children into a DOM node that exists outside the parent component’s hierarchy. This is especially useful for modals, popups, or tooltips that need to visually break out of the parent layout while maintaining React’s virtual DOM functionality.

In class components, state represents local data that the component manages and can change over time using setState(). Props, however, are read-only values passed from parent components and cannot be modified by the child. State is used for dynamic behavior, while props are used for configuration and communication.

shouldComponentUpdate is a lifecycle method used in class components to control whether a re-render should occur when props or state change. Returning false prevents re-rendering, allowing developers to optimize performance by skipping unnecessary updates.

componentDidMount is a lifecycle method that runs once after the component has been inserted into the DOM. It is commonly used for initializing data, starting API calls, setting up subscriptions, or performing side effects that require access to the rendered DOM.