useDidUpdate

Call a function only when dependencies change, not on mount.

Import


import { useDidUpdate } from '@tidbcloud/uikit'

Usage

useDidUpdate works like useEffect, but does not run on mount – only when dependencies change.


import { useState } from 'react'
import { useDidUpdate } from '@tidbcloud/uikit'
import { Button, Text, Group } from '@tidbcloud/uikit'
 
function Demo() {
  const [count, setCount] = useState(0)
  const [updates, setUpdates] = useState(0)
 
  useDidUpdate(() => {
    setUpdates((u) => u + 1)
  }, [count])
 
  return (
    <>
      <Text>Count: {count}</Text>
      <Text>Updates (excluding mount): {updates}</Text>
      <Group>
        <Button onClick={() => setCount((c) => c + 1)}>Increment</Button>
      </Group>
    </>
  )
}

Definition


function useDidUpdate(fn: React.EffectCallback, dependencies?: React.DependencyList): void