state와 reducer 만들 때 타입 지정 import { Provider } from 'react-redux'; import { createStore } from 'redux'; const 초기값 = { count: 0 }; function reducer(state = 초기값, action) { if (action.type === '증가') { return { count : state.count + 1 } } else if (action.type === '감소'){ return { count : state.count - 1 } } else { return initialState } } const store = createStore(reducer); ReactDOM.render( , document...