react-useeffect.js

import React, {useState, useEffect} from 'react';

const UseEffectClickCounter = (props) => {
  const [clicks, setClicks] = useState(initialClicks || 0);
  const incrementClicks = () => {
    setClicks(clicks + 1);
  };
  
  // Introduce our useEffect hook
  useEffect(() => {
    // Every time `clicks` is updated, alert the user!
    alert(`Clicks were updated to ${clicks}`);
  }, [ clicks ]);
  // The useEffect will run whenever the value of `clicks` or any other variable
  // in this dependency list updates
  
  return <>
      <h1>Click Counter</h1>
      <p>Amount of clicks: {clicks}</p>
      <button onClick={incrementClicks}>Click me!</button>
    </>;
};