Question

以前，我数组的结构是：

[
  {
    "id": "Ddfwe23224533",
    "kind": "PEAK_EXPERIENCE",
    "title": "IP - Collective Identity",
  },
  {
    "id": "Ddfwe23224534",
    "kind": "PEAK_EXPERIENCE",
    "title": "IP - Collective Identity 2",
  },
  .....
]

我创建了一个名为flatToHierarchy的函数来对数组中的元素进行分组。这是代码：

export const flatToHierarchy = (arr, prop) => arr.reduce((accumulator, currentItem) => {
  const items = accumulator;
  const propValue = currentItem[prop];
  items[propValue] = items[propValue]
    ? [...items[propValue], currentItem]
    : [currentItem];
  return items;
}, {});

现在，如果我这样称呼它：

flatToHierarchy(elements, 'kind')

它工作正常。

现在，数组的结构已更改。现在看起来像：

[
  {
    "entity": {
      "id": "Ddfwe23224533",
      "kind": "PEAK_EXPERIENCE",
      "title": "IP - Collective Identity",
    },
    entity_id: "jj98834jfj983"
  },
  {
    "entity": {
      "id": "Ddfwe23224534",
      "kind": "PEAK_EXPERIENCE",
      "title": "IP - Collective Identity 2",
    },
    entity_id: "jj98834jfdf83"
  },
  .....
]

因此，现在按元素种类对数组进行分组，我这样称呼：

flatToHierarchy(elements, 'entity.kind')

现在，它给我的东西像：

{
  undefined: [....element1, ....element2 ]
}

但是我想要的是：

{
  PEAK_EXPERIENCE: [....element1, ....element2 ]
}

我对此进行了更深入的研究，发现无法以这种方式访问数组：

array['something.something']

需要通过以下方式进行访问：

array['something']['something']

因此，我更改了功能，但被卡住了。这是我更改的功能：

export const flatToHierarchy = (arr, prop) => arr.reduce((accumulator, currentItem) => {
  const items = accumulator;
  const props = prop.split('.').map(p => [p]);
  console.log(props);
  const propValue = currentItem[prop];
  console.log(currentItem...props); // how to spread the array here?
  items[propValue] = items[propValue]
    ? [...items[propValue], currentItem]
    : [currentItem];
  return items;
}, {});

更新：

当前输入的示例：

[
  {
    "entity": {
      "id": "Ddfwe23224533",
      "kind": "PEAK_EXPERIENCE",
      "title": "IP - Collective Identity",
    },
    entity_id: "jj98834jfj983"
  },
  {
    "entity": {
      "id": "Ddfwe23224534",
      "kind": "PEAK_EXPERIENCE",
      "title": "IP - Collective Identity 2",
    },
    entity_id: "jj98834jfdf83"
  },
  {
    "entity": {
      "id": "Ddfwe23224594",
      "kind": "PEAK_EXPERIENCE2",
      "title": "IP - Collective Identity 6",
    },
    entity_id: "jj98834jfdf33"
  },
]

所需输出的样本：

{
  PEAK_EXPERIENCE: [
    {
      "entity": {
        "id": "Ddfwe23224533",
        "kind": "PEAK_EXPERIENCE",
        "title": "IP - Collective Identity",
      },
      entity_id: "jj98834jfj983"
    },
    {
      "entity": {
        "id": "Ddfwe23224534",
        "kind": "PEAK_EXPERIENCE",
        "title": "IP - Collective Identity 2",
      },
      entity_id: "jj98834jfdf83"
    },
  ],
  PEAK_EXPERIENCE2: [
    {
      "entity": {
        "id": "Ddfwe23224594",
        "kind": "PEAK_EXPERIENCE2",
        "title": "IP - Collective Identity 6",
      },
      entity_id: "jj98834jfdf33"
    },
  ],
}

更新2：

在更改所需的功能时，我需要记住，该功能将始终具有以下指定的签名：

flatToHierarchy(array, string);

示例：

flatToHierarchy(elements, 'kind');

另一个例子：

flatToHierarchy(elements, 'entity.kind');

Answer 1

您正在寻找一个path函数，可以通过使用reduce并向初始对象添加种子来实现。

当心null / undefined属性！

const propValue = prop
  .split('.') // Make a list of all property names (cannot contain a .)
  .reduce((obj, p) => obj[p], currentItem); // Loop over them to traverse your object

const flatToHierarchy = (arr, prop) => arr.reduce((accumulator, currentItem) => {
  const items = accumulator;
  const propValue = prop.split('.').reduce((obj, p) => obj[p], currentItem);
  items[propValue] = items[propValue]
    ? [...items[propValue], currentItem]
    : [currentItem];
  return items;
}, {});

const data = [
  {
    "entity": {
      "id": "Ddfwe23224533",
      "kind": "PEAK_EXPERIENCE",
      "title": "IP - Collective Identity",
    },
    entity_id: "jj98834jfj983"
  },
  {
    "entity": {
      "id": "Ddfwe23224534",
      "kind": "PEAK_EXPERIENCE",
      "title": "IP - Collective Identity 2",
    },
    entity_id: "jj98834jfdf83"
  },
  {
    "entity": {
      "id": "Ddfwe23224594",
      "kind": "PEAK_EXPERIENCE2",
      "title": "IP - Collective Identity 6",
    },
    entity_id: "jj98834jfdf33"
  },
]

console.log(
  flatToHierarchy(data, "entity.kind")
);

Answer 2

考虑到样本输入位于名为 data 的变量中，您可以执行以下操作。

data = data.reduce((output, current) => {
    const kind = current.entity.kind
    output[kind] = (output[kind] || []).concat(current)
    return output
}, {})

通过散布另一个数组对数组进行分组

2 个答案: