What is UseEffect ?

In simple terms, useEffect allows you to run code after a component renders. Purpose and Usage useEffect is crucial because functional components are intended to be pure functions (predictable output given the same input). Operations that interact with the "outside world" need a designated place to run without disrupting the rendering process. Before hooks, these tasks were handled in class components using lifecycle methods. like componentDidMount, componentDidUpdate, and componentWillUnmount. Typical uses: Fetching data from APIs Updating the DOM Setting up subscriptions (e.g., WebSocket) Timers (setTimeout, setInterval) UseEffect Code import { useEffect , useState } from " react " ; function Count () { const [ count , setCount ] = useState ( 0 ) function incre () { setCount ( count + 1 ) console . log ( count ); } useEffect (() => { const interval = setInterval (() => { console . log ( " working " ); }, 1000 ); return (() => { clearInterval ( interval ) }) }) return ( < div > < h1 >