functional-component-with-several-effects.js

function BigClock() {
  function makeClock(intervalInMs) {
    return () => {
      const clockIntervalId = window.setInterval(() => {
        console.log('tick', intervalInMs);
      }, intervalInMs);
      
      return () => {
        window.clearInterval(clockIntervalId);
        console.log('disabled clock')
      };
    }
  }
  
  React.useEffect(makeClock(1000), []);
  React.useEffect(makeClock(2000), []);
  React.useEffect(makeClock(3000), []);
  
  return (
    <p>Clocks are ticking...</p>
  );
}