React Native 出现错误“传播不可迭代实例的尝试无效。” 在将数据添加到空数组时

Question

Trying to add the data in empty array but getting below error in BlogContext file while calling addBlogPost from adddata screen:

Invalid attempt to spread non-iterable instance. In order to be iterable, non-array objects must have a Symbol.iterator method. - node_modules/@babel/runtime/helpers/nonIterableSpread.js:2:22 in _nonIterableSpread - node_modules/@babel/runtime/helpers/toConsumableArray.js:10:111 in _toConsumableArray * src/context/BlogContext.js:6:8 in blogReducer

below is code for BlogContext

import createDataContext from "./createDataContext";

const blogReducer = (state, action) => {
  switch (action.type) {
    case "add_blogpost":
      return [
        ...state,
        {
          id: Math.floor(Math.random() * 9999),
          title: action.payload.title,
          content: action.payload.content,
        },
      ];
    case "edit_blogpost":
      return state;
    case "delete_blogpost":
      return state.filter((blogPost) => blogPost.id != action.payload);
    default:
      return state;
  }
};

const addBlogPost = (dispatch) => {
  return (title, content, callBack) => {
    dispatch({
      type: "add_blogpost",
      payload: { title: title, content: content },
    });

    callBack();
  };
};

const deleteBlogPost = (dispatch) => {
  return (id) => {
    dispatch({ type: "delete_blogpost", payload: id });
  };
};

export const { Context, Provider } = createDataContext(
  blogReducer,
  { addBlogPost },
  { deleteBlogPost },
  []
);

Answer 1

const blogReducer = (state, action) 

state here is undefined at the begining so try this

const blogReducer = (state = [], action) 

Answer 2

Its working fine now,, i am doing mistake in below code:

export const { Context, Provider } = createDataContext(
  blogReducer,
  { addBlogPost },
  { deleteBlogPost },
  []
);

these { addBlogPost }, { deleteBlogPost }, two should be in same object like {addBlogPost, deleteBlogPost}, only this change make it work, Thanks for all the help