Advanced React Hooks

tutorialDetail.content.react-hooks.s1_code

// useMemo: Memoize calculated values
const filteredProducts = useMemo(() => {
  return products.filter(p => p.price > minPrice)
}, [products, minPrice])

// useCallback: Memoize functions
const handleSearch = useCallback((query: string) => {
  setSearchTerm(query)
  fetchResults(query)
}, [fetchResults])

// hooks/useLocalStorage.ts
function useLocalStorage<T>(key: string, initialValue: T) {
  const [storedValue, setStoredValue] = useState<T>(() => {
    try {
      const item = window.localStorage.getItem(key)
      return item ? JSON.parse(item) : initialValue
    } catch {
      return initialValue
    }
  })

  const setValue = (value: T) => {
    setStoredValue(value)
    window.localStorage.setItem(key, JSON.stringify(value))
  }

  return [storedValue, setValue] as const
}

tutorialDetail.content.react-hooks.s4_code