React.StrictMode

What is React.StrictMode?
'React.StrictMode' is a tool provided by React that helps developers write more resilient code by highlighting potential problems and deprecated features in their application during development. When you wrap components with '<React.StrictMode>', React performs additional checks and warnings to help identify common issues such as:

1. Identifying unsafe lifecycle methods usage.
2. Warning about legacy string ref usage.
3. Detecting state updates inside 'render' methods.
4. Spotting unexpected side effects during rendering.
5. Highlighting potential problems with context usage.

By using 'React.StrictMode', you can catch and fix these issues earlier in the development process, which can lead to fewer bugs and better performance in your application.

It's important to note that 'React.StrictMode' only activates in development mode. In production builds, it has no effect and does not impact the behavior of your application.

To use 'React.StrictMode', you simply wrap your root component (usually located in 'src/index.js' or 'src/App.js') with '<React.StrictMode>'

Example

import React from "react";
import ReactDOM from "react-dom";
import App from "./App";

ReactDOM.render(
  <React.StrictMode>
    <App />
  </React.StrictMode>,
  document.getElementById("root")
);

By doing this, all components inside '<App />' will be subject to the additional checks provided by 'React.StrictMode'. Once you've identified and fixed any issues highlighted by 'React.StrictMode', you can remove the wrapper in your production code if desired.