ReasonJun

React.memo To fix the comparison method used by React.memo for prop comparison, you can provide a custom comparison function as the second argument to React.memo. This custom comparison function determines whether the component should be re-rendered by comparing the previous props with the next props. The custom comparison function receives two arguments: prevProps and nextProps. It should retur..

React.memo is a higher-order component (HOC) provided by React that aims to optimize functional components by preventing unnecessary re-renders. It is similar to the PureComponent class component optimization but designed for functional components. By wrapping a functional component with React.memo, React will automatically memoize the component and only re-render it if its props have changed. I..

App.js code : import { useEffect, useState } from 'react'; import './App.css'; import B from './components/B'; import A from './components/A'; function App() { const [value, setValue] = useState(''); const [posts, setPosts] = useState([]); useEffect(() => { fetch('https://jsonplaceholder.typicode.com/posts') .then((res) => res.json()) .then((posts) => setPosts(posts)); }, []); return ( setValue(..