`usePrevious`

Tracks the value from the previous render / tracked update. Returns undefined on the first run.


import { useEffect } from 'react'
import { usePrevious } from '@wire-ui/react'
 
function Counter({ count }: { count: number }) {
  const previous = usePrevious(count)
 
  useEffect(() => {
    if (previous !== undefined && count > previous) {
      console.log(`went up by ${count - previous}`)
    }
  }, [count, previous])
 
  return <span>{count}</span>
}

Parameters

Param	Type	Description
`value`	`T`	Value to track.

Returns

T | undefined — the value from the previous render, or undefined before the first update.