useEffect example from React Hooks

ComponentWithUseEffect.js

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

function ComponentWithUseEffect() {
  const [screenWidth, setScreenWidth] = useState(0);

  const updateScreenWidth = () => {
    const currentScreenWidth = window.innerWidth;
    setScreenWidth(currentScreenWidth);
  };

  useEffect(() => {
    updateScreenWidth();
    window.addEventListener("resize", updateScreenWidth);
    return () => window.removeEventListener("resize", updateScreenWidth);
  }, []);

  return (
    <p>Screen Width: {screenWidth}</p>
  );
}

export default ComponentWithUseEffect;