StrictMode is a tool added in version 16.3 of React to highlight potential problems in an application.
It performs additional checks on the application. function App() { return ( <React.StrictMode> <div classname="App"> <Header/> <div> Page Content </div> <Footer/> </div> </React.StrictMode> ); } To enable StrictMode, <React.StrictMode> tags need to be added inside the application: import React from "react"; import ReactDOM from "react-dom"; import App from "./App"; const rootElement = document.getElementById("root"); ReactDOM.render( <React.StrictMode> <App /> </React.StrictMode>, rootElement ); StrictMode currently helps with the following issues: Identifying components with unsafe lifecycle methods: Certain lifecycle methods are unsafe to use in asynchronous react applications.
With the use of third-party libraries, it becomes difficult to ensure that certain lifecycle methods are not used.
StrictMode helps in providing us with a warning if any of the class components use an unsafe lifecycle method.
Warning about the usage of legacy string API: If one is using an older version of React, callback ref is the recommended way to manage refs instead of using the string refs.
StrictMode gives a warning if we are using string refs to manage refs.
Warning about the usage of findDOMNode: Previously, findDOMNode( ) method was used to search the tree of a DOM node.
This method is deprecated in React.
Hence, the StrictMode gives us a warning about the usage of this method.
Warning about the usage of legacy context API (because the API is error-prone).
StrictMode is a tool added in version 16.3 of React to highlight potential problems in an application.
It performs additional checks on the application. function App() { return ( <React.StrictMode> <d...