React Redux:如何基于将要更改的数据创建状态对象，以及如何更新每个对象中的单个元素

import { createStore, combineReducers } from 'redux';

// 定义reducer函数
function todosReducer(state = [], action) {
  switch (action.type) {
    case 'ADD_TODO':
      return [...state, action.payload];
    case 'REMOVE_TODO':
      return state.filter(todo => todo.id !== action.payload);
    default:
      return state;
  }
}

function counterReducer(state = 0, action) {
  switch (action.type) {
    case 'INCREMENT':
      return state + 1;
    case 'DECREMENT':
      return state - 1;
    default:
      return state;
  }
}

// 组合reducer函数
const rootReducer = combineReducers({
  todos: todosReducer,
  counter: counterReducer
});

// 创建store
const store = createStore(rootReducer);

// 输出初始状态
console.log(store.getState());

// 输出：{ todos: [], counter: 0 }

function todosReducer(state = [], action) {
  switch (action.type) {
    case 'UPDATE_TODO':
      return state.map(todo => {
        if (todo.id === action.payload.id) {
          return { ...todo, ...action.payload.updatedTodo };
        }
        return todo;
      });
    default:
      return state;
  }
}