如何将JSON对象转换为Typescript数组？

Question

我有一个API请求，返回以下内容：

{"page": 1,
  "results": [
    {
      "poster_path": "/9O7gLzmreU0nGkIB6K3BsJbzvNv.jpg",
      "adult": false,
      "overview": "Framed in the 1940s for the double murder of his wife and her lover, upstanding banker Andy Dufresne begins a new life at the Shawshank prison, where he puts his accounting skills to work for an amoral warden. During his long stretch in prison, Dufresne comes to be admired by the other inmates -- including an older prisoner named Red -- for his integrity and unquenchable sense of hope.",
      "release_date": "1994-09-10",
      "genre_ids": [
        18,
        80
      ],
      "id": 278,
      "original_title": "The Shawshank Redemption",
      "original_language": "en",
      "title": "The Shawshank Redemption",
      "backdrop_path": "/xBKGJQsAIeweesB79KC89FpBrVr.jpg",
      "popularity": 5.446135,
      "vote_count": 5250,
      "video": false,
      "vote_average": 8.32
    },
    {
      "poster_path": "/lIv1QinFqz4dlp5U4lQ6HaiskOZ.jpg",
      "adult": false,
      "overview": "Under the direction of a ruthless instructor, a talented young drummer begins to pursue perfection at any cost, even his humanity.",
      "release_date": "2014-10-10",
      "genre_ids": [
        18,
        10402
      ],
      "id": 244786,
      "original_title": "Whiplash",
      "original_language": "en",
      "title": "Whiplash",
      "backdrop_path": "/6bbZ6XyvgfjhQwbplnUh1LSj1ky.jpg",
      "popularity": 9.001948,
      "vote_count": 2072,
      "video": false,
      "vote_average": 8.28
    },

我想在单击按钮后使用以下代码显示获取的电影标题：

import {Component} from '@angular/core';
import {Http, Response} from '@angular/http';

@Component({
  selector: 'http',
  template: `

<button (click)="makeRequest()">Make Request</button>

<table class="table table-striped">
      <thead>
        <tr>
          <th>Title</th>
         </tr>
      </thead>

        <tbody>
        <tr *ngFor="let movie of data">
          <td>{{movie.title}}</td>
        </tr>

      </tbody>
    </table>
`
})
export class AppComponent {

  data: Object;

  constructor(public http: Http) {
  }
  makeRequest(): void {

    this.http.request('http://api.themoviedb.org/3/movie/top_rated?api_key=API-KEY')
      .subscribe((res: Response) => {
        this.data = res.json();

      });
  }

}

我的问题是，我收到一条错误消息，提示我只能遍历数组，并且我的数据是对象。如何在打字稿中将Object转换为Array，并在表格中显示电影的标题？

Answer 1

没错，您的回复是一个带有字段的对象：

{
    "page": 1,
    "results": [ ... ]
}

因此，您实际上只想迭代该results字段：

this.data = res.json()['results'];

…甚至更简单：

this.data = res.json().results;