blog-things-to-avoid-when-using-react-hooks-3.js

import React, { useEffect } from 'react';

function MyComponent() {
  useEffect(() => {
    // Run once after DOMContentEvent loads
  }, []);
  
  useEffect(() => {
    // Synchronize the state with the state of this component.
    return function cleanup() {
      // Cleanup the previous side-effect before running a new one
    }
    // Run the side-effect and it's cleanup to for the re-run
  }, [a, b ,c, d]); // When any of these change
  
  useEffect(() => {
    // Run every single time this component is re-rendered
  });
  
  return {
    // Render React elements
  }
}