What is strict mode in React.js?

Answer

React.StrictMode is a useful component for highlighting potential problems in an application.
Just like <Fragment>, <StrictMode> does not render any extra DOM elements.
It activates additional checks and warnings for its descendants.
These checks apply for development mode only.

import React from 'react'

function Application() {
return (
<div>
<Header />
<React.StrictMode>
<div>
<ComponentOne />
<ComponentTwo />
</div>
</React.StrictMode>
<Header />
</div>
)
}