In React, you don’t have access to the previous render’s value. This is usually fine, but once in a while I find myself needing to access the previous values of a state for diverse reasons (e.g. recording analytics event on certain behaviours).

In that case, I use a custom hook called usePreviousValue:

import { useEffect, useRef } from 'react'

export default function usePreviousValue(value) {
  const ref = useRef()
  useEffect(() => {
    ref.current = value
  return ref.current

It can be used this way:

const previousCount = usePreviousValue(count)
useEffect(() => {
    if (previousCount && previousCount > count) {
}, [previousCount, count])