我如何从下面给定的json中获取演员名称的值。我可以获取其余值，但不能获取演员名称

这是我的JSON响应的样子。我可以获取id和title等的值，但不能获取actor，因为actor是json对象内的另一个数组。下面是我的反应代码的样子。我尝试了几种方法，但总是以未定义属性的错误结束。

```
    {
    actor: [
    {
    name: "Leonardo DiCaprio"
    },
    {
    name: "Kate Winslet"
    }
    ],
    _id: "5e973eef8af37634940e9a5b",
    title: "Titanic",
    director: "James Cameron",
    genre: "Romantic",
    imageURL: ";url=https%3A%2F%2Fencrypted-tbn0.gstatic%2Fimages%3Fq%3Dtbn%3AANd9GcQhYjUIu2o5v5u3rfJpCq5Cz0Q9WK--XdYxai_N2d0ImohPiIOp&psig=AOvVaw1SjoYtMGvlUsg-hW-iHO8c&ust=1588932208988000&source=images&cd=vfe&ved=0CA0QjhxqFwoTCMjSivG_oekCFQAAAAAdAAAAABAD",
    __v: 0
    }

```

我的React代码看起来像这样。

```
class MovieDetails extends Component 
    {
        constructor(props) {
          super(props);
          this.state = {
            movie: [],

            isLoaded: false,
          }

        }      
        componentWillMount() {
            let id = this.props.id;
            fetch(`http://localhost:5000/movie/details/${id}`)
            .then(res => {
              return res.json();})
            .then(movie => {
                this.setState({ movie });
            })

            .catch(console.log('error'));
        }        
        render() {
          return (
            <div className="container">
            <div className ="centre">
            <div className="col-xs-12"> 
            {this.state.movie.map((movie => (                  

                <div class="container" >
                    <div>
                        <h3>{movie.title}</h3>
                        <img src={movie.imageURL}  className="img-responsive"  height = "120" width ="120"/>
                        <h5 className="card-genre" >Genre : {movie.genre}</h5>
                        <h5 className="card-director">Directed by : {movie.director}</h5>

                    </div>
                </div>


            )
          ))}

          </div>
         </div>
         </div>
        );
      }
    }
    export default MovieDetails;
```

尝试在div中使用此代码

  {
    movie.actor.map(actor=>(
     <div>{actor.name}</div>
    ))
  }