Javascript嵌套数组到对象转换

Question

我有如下格式的对象数组。它基本上是一个嵌套的对象数组。我试图使用递归函数来完成它，但是我未能组织嵌套的对象。

[
  {
    "id": "31a3sd2f1a3ds21f",
    "name": "Energy device",
    "child": [
      {
        "id": "65sa4d65a4sdf654adsf",
        "name": "Device 2",
        "child": [
          {
            "id": "65a4d65ad4s54adsf",
            "name": "Device 3",
            "child": []
          }
        ]
      }
    ]
  },
  {
    "id": "6as54d54as5f",
    "name": "Energy device 2",
    "child": [
      {
        "id": "9a8s7df98a78sdf",
        "name": "Device 4",
        "child": [
          {
            "id": "65a4d65ad4s54adsf",
            "name": "Device 5",
            "child": []
          }
        ]
      },
      {
        "id": "65asd54as5f4",
        "name": "Device 5-1",
        "child": []
      }
    ]
  }
]

我想把它转换成以下格式。

{
  "31a3sd2f1a3ds21f": {
    "65sa4d65a4sdf654adsf": {
      "65a4d65ad4s54adsf": ""
    }
  },
  "6as54d54as5f": {
    "9a8s7df98a78sdf": {
      "65a4d65ad4s54adsf": ""
    },
    "65asd54as5f4": ""
  }
}

有人能帮我吗？

Answer 1

您可以将数组中的每个对象映射到形状[key, value]的新数组。对于每个对象，可以在回调参数({id, child}) => ...)中使用去剪切赋值提取id和子属性。然后，可以为该对象返回一个数组，该数组表示您构建的新对象的条目。键是当前对象的id，该值要么是一个基于child数组的新对象，可以通过递归调用来构建，要么是一个空字符串，如果您的当前对象没有任何子对象。这允许您在构建对象时将嵌套添加到对象中。最后，可以将arr的映射版本封装为对Object.fromEntries()的调用，该调用允许将[key, value]对条目的数组转换为对象：

​

const arr = [ { "id": "31a3sd2f1a3ds21f", "name": "Energy device", "child": [ { "id": "65sa4d65a4sdf654adsf", "name": "Device 2", "child": [ { "id": "65a4d65ad4s54adsf", "name": "Device 3", "child": [] } ] } ] }, { "id": "6as54d54as5f", "name": "Energy device 2", "child": [ { "id": "9a8s7df98a78sdf", "name": "Device 4", "child": [ { "id": "65a4d65ad4s54adsf", "name": "Device 5", "child": [] } ] }, { "id": "65asd54as5f4", "name": "Device 5-1", "child": [] } ] } ];

const mapToId = (arr) => Object.fromEntries(arr.map(({id, child}) => [
  id, child.length ? mapToId(child) : ""
]));

const res = mapToId(arr);
console.log(res);

​

Answer 2

我不知道为什么您希望最后一个子对象是空字符串而不是空对象，但如下所示：

function arrayToObject(array) {
    // Create empty object if array has cildren, else create an empty string
    const obj = array.length > 0 ? {} : '';

    // Recursively add children to object
    array.forEach((item) => {
        obj[item.id] = arrayToObject(item.child);
    });

    return obj;
}