How to call useEffect React Hook on a component mount and unmount

These can be replaced with proper use of useEffect hook introduced in React version 16.8.

Here is the code that will run exactly once when a component is mounted and exactly once when it's supposed to be unmounted:

import { useEffect } from "React";

const ExampleComponent = () => {
  useEffect(() => {
    // Here goes the code you wish to run on mount

    return () => {
      // Here goes the code you wish to run on unmount
    }
  }, []);

  ...
}

It's crucial to pass an empty array as the second argument of useEffect function call. If you omit it or pass dependencies inside of array it won't work as intended.