React ContextAPI 사용법

(App.js)

export let 재고context = React.createContext();

function App(){
  let [재고, 재고변경] = useState([10,11,12]);

  return (
    <HTML많은곳/>
    <재고context.Provider value={재고}>
      <Detail/>
    </재고context.Provider>
  )
}

=====================================

(Detail.js)

import {재고context} from './App.js';

function Detail(){
  let 재고 = useContext(재고context);

  return (
    <HTML많은곳/>
  )
}