Saber2pr's Blog


GetDerivedStateFromProps similar to class components

import { useState, useMemo, useRef } from 'react'

export function useDerivedStateFromProps<T>(s: T): [T, (s: T) => void] {
  const stateRef = useRef<T>(s)
  const [_, forceUpdate] = useState({})

  useMemo(() => {
    stateRef.current = s
  }, [s])

  const setState = (s: T) => {
    stateRef.current = s

  return [stateRef.current, setState]

Solve what problem? Props, as state, updates state when props changes Why not use useEffect to listen to props and then setState? When the parent component is updated, the child component will render twice, the parent component render children once, and the setState in the effect once. Additional setState can be removed by using ref.