是这样的，我有一个obj,是一个json里面嵌套了一个array,数据入下：

[ '炒菜': [ { dishName: '鱼香肉丝',
      price: 25,
      intro: 'test',
      index: 1,
      category: '炒菜',
      _id: 57666d75c8f2cb97bb07e50b,
      dishPic: 'http://localhost:8080/resources/5766671c1002808fbbd09ebd/dishes/57666d75c8f2cb97bb07e50b.jpg',
      comment: [],
      tags: [Object] },
    { dishName: '宫保板筋',
      price: 23,
      intro: '',
      index: 0,
      category: '炒菜',
      _id: 57666d75c8f2cb97bb07e50a,
      dishPic: 'http://localhost:8080/resources/5766671c1002808fbbd09ebd/dishes/57666d75c8f2cb97bb07e50a.jpg',
      comment: [],
      tags: [Object] } ],
  '火锅': [ { dishName: '海底捞',
      price: 250,
      intro: 'test',
      index: 3,
      category: '火锅',
      _id: 57666d75c8f2cb97bb07e50d,
      dishPic: 'http://localhost:8080/resources/5766671c1002808fbbd09ebd/dishes/57666d75c8f2cb97bb07e50d.jpg',
      comment: [],
      tags: [Object] },
    { dishName: '黑豆花肉圆子火锅',
      price: 80,
      intro: 'test',
      index: 2,
      category: '火锅',
      _id: 57666d75c8f2cb97bb07e50c,
      dishPic: 'http://localhost:8080/resources/5766671c1002808fbbd09ebd/dishes/57666d75c8f2cb97bb07e50c.jpg',
      comment: [],
      tags: [Object] } ],
  '燃烧': [ { dishName: '凌波',
      price: 123,
      intro: 'test',
      index: 4,
      category: '燃烧',
      _id: 57666d75c8f2cb97bb07e50e,
      dishPic: 'http://localhost:8080/resources/5766671c1002808fbbd09ebd/dishes/57666d75c8f2cb97bb07e50e.jpg',
      comment: [],
      tags: [Object] } ] ]
      

我发现res.send(obj)不工作，在 postman里面显示为空

res.json(obj)也不行

但是res.send(obj["火锅"])就可以的，但是我想要一次发送完，请问怎么弄？