javascript - React JS，Redux状态更新错误，无法读取属性Symbol(Symbol.iterator)

Question

当我更新 redux 状态时，它给出错误 TypeError: object is not iterable (cannot read property Symbol(Symbol.iterator))

const initialState = {
  articles: []
};

function rootReducer(state = initialState, action) {
 switch(action.type){
   case ADD_ARTICLE:{return [...state,action.payload];}  # error occurs in this line
   default:return state;
 }
}

export default rootReducer;

Answer 1

您正在尝试克隆 {} 而非 [] 的状态。尝试按以下方式返回:

switch(action.type) {
   case ADD_ARTICLE: {
     return {
        ...state,
        action.payload
     };
   }

   default: {
     return ...state;
   }
}