Why does React do this?

Question

React

Why do React components (function and class) 'render' 2 times before rendering or other update?

Answer 1

I'll play Wang. Most likely you have wrapped the component in StrictMode and are in the development environment. In this case, the components will be rendered twice when mounted to perform internal StrictMode checks.
https://github.com/facebook/react/issues/15074#iss...