Strict mode in react

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

ReactDOM.render(
  
    
  ,
  document.getElementById('root')
);

Once you have enabled strict mode, you will start seeing additional warnings in your browser console.

Strict mode does not affect the production build of your application and should only be used during development. To enable strict mode in your React application, simply wrap your root component with the component.

Strict mode is a development mode feature that was introduced in React version 16.3.

Strict mode is a development mode in React that helps identify potential problems in your code and enforce best practices. When you enable Strict mode, React will perform additional checks and warnings that help you catch and fix common issues in your code.

Some of the features of Strict mode include:

1. Identifying unsafe lifecycle methods and deprecated features
2. Detecting unexpected side effects in your code
3. Highlighting potential problems with type checking and prop validation
4. Detecting issues with state updates and render cycles
5. Detecting errors related to the usage of useContext, useReducer, and useRef hooks.

To enable Strict mode, you can simply wrap your application or a specific component with the component, you can ensure that your code is being checked for potential issues during development, and you can fix those issues before they become problems in production. However, it's important to note that Strict mode should only be used in the development and not in production as it can have a performance impact.

StrictMode is a React Developer Tool that is primarily used to identify potential issues in a web application. For its descendant components, it activates additional deprecation checks and warnings.

StrictMode is a tool for highlighting potential problems in an application. Like Fragment, StrictMode does not render any visible UI. It activates additional checks and warnings for its descendants.

You can enable StrictMode adding tag. 

Example

import React from 'react';

function ExampleApplication() {
  return (
    

      

      
        

          
          
        
      
      
  );
}

https://reactjs.org/docs/strict-mode.html