Used in the Medium article: Dark Mode for ANY React App 2019: Part 1 of a Series on Day/Night Toggles

use-dark-mode-in-two-lines-of-code.js

import useDarkMode from "use-dark-mode"; // Don't forget to import the NPM package use-dark-mode
function darkModeToggleButton() {
  const darkMode = useDarkMode(false);
  return (<button onClick={darkMode.toggle}>Toggle Day / Night</button>);
}