为什么我会收到未定义的 map 的 TypeError？

Question

I'm working on a React project and im getting this error of undefined map. We are currently doing some tests too and we are mocking an array with details in it. I don't know if it is a syntax error or i'm not passing the props right.

Here's my code

Event.js

import Button from 'react-bootstrap/Button'

class Event extends Component {
  state = {
    collapsed:  true,
    
  }

  handleClick = () => {
    this.setState({
      collapsed: !this.state.collapsed,
    });
  };


  render() {
    const  { event }  = this.props;
    const { collapsed } = this.state;
    return (
      <div className="event">
         <h2 className="summary">{event.summary}</h2>
         <p className="start-date">
          {event.start.dateTime}
        </p>
        <p className="end-date">
          {event.end.dateTime}
        </p>
        <p className="location">
          {event.location}
        </p>
        <Button variant="outline-info"
          className={`${collapsed ? "show" : "hide"}-details`}
          onClick={this.handleClick}
        >
          {collapsed ? "Show Details" : "Hide Details"}
        </Button>
        {!collapsed &&
          <div className={`extra-details ${this.state.collapsed ? "hide" : "show"}`}>
            <p className="event-description">{event.description}</p>
          </div>
        }
        </div>

    )
  }
}
export default Event;

EventList.js:

import Button from 'react-bootstrap/Button'

class Event extends Component {
  state = {
    collapsed:  true,
    
  }

  handleClick = () => {
    this.setState({
      collapsed: !this.state.collapsed,
    });
  };


  render() {
    const  { event }  = this.props;
    const { collapsed } = this.state;
    return (
      <div className="event">
         <h2 className="summary">{event.summary}</h2>
         <p className="start-date">
          {event.start.dateTime}
        </p>
        <p className="end-date">
          {event.end.dateTime}
        </p>
        <p className="location">
          {event.location}
        </p>
        <Button variant="outline-info"
          className={`${collapsed ? "show" : "hide"}-details`}
          onClick={this.handleClick}
        >
          {collapsed ? "Show Details" : "Hide Details"}
        </Button>
        {!collapsed &&
          <div className={`extra-details ${this.state.collapsed ? "hide" : "show"}`}>
            <p className="event-description">{event.description}</p>
          </div>
        }
        </div>

    )
  }
}
export default Event;

App.js

import './App.css';
import EventList from './EventList';
import CitySearch from './CitySearch';
import NumberOfEvents from './NumberOfEvents';

function App() {
  return (
    <div className="App">
      <CitySearch />
      <NumberOfEvents />
      <EventList />
    </div>
  );
}

export default App;

The error appears in the EventList.js file enter image description here

Answer 1

const mockData = [
  {
      "kind": "calendar#event",
      "etag": "\"3181161784712000\"",
      "id": "4eahs9ghkhrvkld72hogu9ph3e_20200519T140000Z",
      "status": "confirmed",
      "htmlLink": "https://www.google.com/calendar/event?eid=NGVhaHM5Z2hraHJ2a2xkNzJob2d1OXBoM2VfMjAyMDA1MTlUMTQwMDAwWiBmdWxsc3RhY2t3ZWJkZXZAY2FyZWVyZm91bmRyeS5jb20",
      "created": "2020-05-19T19:17:46.000Z",
      "updated": "2020-05-27T12:01:32.356Z",
      "summary": "Learn JavaScript",
      "description": "Have you wondered how you can ask Google to show you the list of the top ten must-see places in London? And how Google presents you the list? How can you submit the details of an application? Well, JavaScript is doing these. :) \n\nJavascript offers interactivity to a dull, static website. Come, learn JavaScript with us and make those beautiful websites.",
      "location": "London, UK",
      "creator": {
       "email": "fullstackwebdev@careerfoundry.com",
       "self": true
      },
      "organizer": {
       "email": "fullstackwebdev@careerfoundry.com",
       "self": true
      },
      "start": {
       "dateTime": "2020-05-19T16:00:00+02:00",
       "timeZone": "Europe/Berlin"
      },
      "end": {
       "dateTime": "2020-05-19T17:00:00+02:00",
       "timeZone": "Europe/Berlin"
      },
      "recurringEventId": "4eahs9ghkhrvkld72hogu9ph3e",
      "originalStartTime": {
       "dateTime": "2020-05-19T16:00:00+02:00",
       "timeZone": "Europe/Berlin"
      },
      "iCalUID": "4eahs9ghkhrvkld72hogu9ph3e@google.com",
      "sequence": 0,
      "reminders": {
       "useDefault": true
      },
      "eventType": "default"
     },
     {
      "kind": "calendar#event",
      "etag": "\"3181159875584000\"",
      "id": "3qtd6uscq4tsi6gc7nmmtpqlct_20200520T120000Z",
      "status": "confirmed",
      "htmlLink": "https://www.google.com/calendar/event?eid=M3F0ZDZ1c2NxNHRzaTZnYzdubW10cHFsY3RfMjAyMDA1MjBUMTIwMDAwWiBmdWxsc3RhY2t3ZWJkZXZAY2FyZWVyZm91bmRyeS5jb20",
      "created": "2020-05-19T19:14:30.000Z",
      "updated": "2020-05-27T11:45:37.792Z",
      "summary": "React is Fun",
      "description": "Love HTML, CSS, and JS? Want to become a cool front-end developer? \n\nReact is one of the most popular front-end frameworks. There is a huge number of job openings for React developers in most cities. \n\nJoin us in our free React training sessions and give your career a new direction. ",
      "location": "Berlin, Germany",
      "creator": {
       "email": "fullstackwebdev@careerfoundry.com",
       "self": true
      },
      "organizer": {
       "email": "fullstackwebdev@careerfoundry.com",
       "self": true
      },
      "start": {
       "dateTime": "2020-05-20T14:00:00+02:00",
       "timeZone": "Europe/Berlin"
      },
      "end": {
       "dateTime": "2020-05-20T15:00:00+02:00",
       "timeZone": "Europe/Berlin"
      },
      "recurringEventId": "3qtd6uscq4tsi6gc7nmmtpqlct",
      "originalStartTime": {
       "dateTime": "2020-05-20T14:00:00+02:00",
       "timeZone": "Europe/Berlin"
      },
      "iCalUID": "3qtd6uscq4tsi6gc7nmmtpqlct@google.com",
      "sequence": 0,
      "reminders": {
       "useDefault": true
      },
      "eventType": "default"
     }
]
     export { mockData };
     ```