如何对数组obj进行分组？

Question

我是数组obj分组的新手。我尝试了以下的方法，我相信我已经达到了目的，但是我缺少了一些东西，我不明白在哪里。

Doing:

const result = data.map(function(item) {
  const ditem = dictionary.find(d => d.state == item.state);
  if(ditem) {
    return {
      ...item,
      "lat": ditem.lat ,
      "long": ditem.long
    }
  }
  return item;
});
console.log(result);

const formatted = result.map(area => {
  return {
    "state": area["state"],
    "lat": area["lat"],
    "long": area["long"],
    "datasets": Object.keys(area)
    .map(date => ({ date: area[date], negative: area[date]}))
  };
});

给我：

[
  {
    "state": "AK",
    "lat": "9875.33.00",
    "long": "-8371.42.00",
    "datasets": [
      {
        "date": 20200421,
        "negative": 20200421
      },
      {
        "date": "AK",
        "negative": "AK"
      },
      {
        "date": 329,
        "negative": 329
      },
      {
        "date": 10790,
        "negative": 10790...

期待的例子：

0:
  State: "AK", 
  Lat: 45.0732745
  Long: 7.680687483
  0: date: "2/24/20"
     positive: 329
     negative: 10790
     pending: null
     hospitalizedCurrently: 42
     hospitalizedCumulative: 36...
  1: 
     date: "2/25/20",
     positive: 329
     negative: 10790
     pending: null
     hospitalizedCurrently: 42
     hospitalizedCumulative: 36...

Answer 1

这可能是你要找的代码。

const formatted = Object.assign({},result.map(area => {
  return {
    "state": area["state"],
    "lat": area["lat"],
    "long": area["long"],
    "datasets": Object.assign({},Object.keys(area)
    .map(date => ({ date: area[date], negative: area[date]})))
  };
}))