在reactjs中以现有状态添加动态对象变量（使用功能组件）

Question

我是reactjs和创建小项目的新手，我使用的是功能组件而不是类组件，并使用store for state。我添加了一些状态变量，并希望在退出状态下添加对象数组，我试过但它不起作用。下面是我的商店文件，其中设置状态：

export const initialState = {
  validationTally: 0,
  token: '',
  multiForm : []
  }

  // action types
const SET_VALIDATION_TALLY = 'SET_VALIDATION_TALLY';
const SET_TOKEN = 'SET_TOKEN';
const SET_MULTIFORM = 'SET_MULTIFORM';

export const reducer = (state, action) => {
    switch (action.type) {
        case SET_VALIDATION_TALLY:
          return {
            ...state,
            validationTally: state.validationTally + 1
          };
        case SET_TOKEN:
          return {
            ...state,
            token: action.payload
          };
        case SET_MULTIFORM:
          return {
            ...state,
            multiForm: action.payload
        };
    }
}

export const setValidationTally = () => ({
  type: SET_VALIDATION_TALLY
});

export const setToken = payload => ({
  type: SET_TOKEN,
  payload
});

export const setMultiForm = payload => ({
  type: SET_MULTIFORM,
  payload
});

我想动态地在状态变量“multiForm”中添加对象，当有人输入值2时我想在“multiForm”中添加两个对象，如下所示

export const initialState = {
  validationTally: 0,
  app: '',
  token: '',
  multiForm : [{
    firstName : '',   
    lastName :''
  },
  {
    firstName : '',   
    lastName :''
  }]
  }

Answer 1

假设用于action.payload动作的SET_MULTIFORM包含要添加的字段数，您可以简单地映射数组项并添加到现有字段

case SET_MULTIFORM:
      return {
        ...state,
        multiForm: [...state.multiForm, ...Array.from({ length: action.payload }).map(() => ({firstName: '', lastName: ''}))]
    };