usePrevious React Hook

index.js

import React, { useState } from "react";
import usePrevious from "./usePrevious";

const App = () => {
  const [count, setCount] = useState(0);
  const prevCount = usePrevious(count);

  return (
    <>
      <p>Count: {count} - Previous Count: {prevCount || 0}</p>
      <button onClick={() => setCount(count + 1)}>Add</button>
    </>
  );
};

usePrevious.js

import { useEffect, useRef } from "react";

export default (value) => {
  const ref = useRef();

  useEffect(() => {
    ref.current = value;
  });

  return ref.current;
};