Strict Mode effect behavior

Learn Strict Mode effect behavior in React with a dedicated explanation, a concept-specific example, a production caution, and a mastery check.

12 min read • Intermediate

react-024.tsx

tsx

import { StrictMode,useEffect } from "react";
function Demo(){ useEffect(()=>{ console.log("setup"); return()=>console.log("cleanup") },[]); return <p>Check development console</p>; }
export default function App(){ return <StrictMode><Demo/></StrictMode>; }

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