javascript - 如何访问存储在由一个字段链接的数组对象中的两个数据？

Question

我有一个 REST API，我从中获取 json 数据并将它们存储在数组中。 API 如下所示:

[


    {
        "id": "100",
        "name": "Person1",
        "number": "+91-8980439023"
      },
      {
        "id": "102",
        "name": "Person2",
        "number": "+91-5980339023"
      },
      {
        "id": "105",
        "name": "Person3",
        "number": "+91-8980439023"
      },
      {
        "id": "101",
        "name": "Person4",
        "number": "+91-8980439023",
        "parent": "105"
      },
      {
        "id": "110",
        "name": "Person5",
        "number": "+91-8980439023"
      },
      {
        "id": "115",
        "name": "Person6",
        "number": "+91-9834295899",
        "parent": "100"
      }
    ]

一些数据有“parent”字段。“parent”字段中的值是其他数据的“id”。现在我想将这些在其他数据的“父”字段中有引用的数据存储在一个单独的数组中。例如: id=101 的数据具有值为 105 的“父”键，这又是第三个数据的 id。因此 id=105 的数据应存储在单独的数组中。

我怎样才能以简单且可扩展的方式进行操作？

Answer 1

尝试

let parents = data.filter(d=> data.some(c=> c.parent==d.id));

let data = [
    {
        "id": "100",
        "name": "Person1",
        "number": "+91-8980439023"
      },
      {
        "id": "102",
        "name": "Person2",
        "number": "+91-5980339023"
      },
      {
        "id": "105",
        "name": "Person3",
        "number": "+91-8980439023"
      },
      {
        "id": "101",
        "name": "Person4",
        "number": "+91-8980439023",
        "parent": "105"
      },
      {
        "id": "110",
        "name": "Person5",
        "number": "+91-8980439023"
      },
      {
        "id": "115",
        "name": "Person6",
        "number": "+91-9834295899",
        "parent": "100"
      }
    ];
    
let parents = data.filter(d=> data.some(c=> c.parent==d.id));

console.log(parents);

要有 O(2n) 的复杂度，首先将父 id 放入某个哈希表，然后进行过滤

let data = [
    {
        "id": "100",
        "name": "Person1",
        "number": "+91-8980439023"
      },
      {
        "id": "102",
        "name": "Person2",
        "number": "+91-5980339023"
      },
      {
        "id": "105",
        "name": "Person3",
        "number": "+91-8980439023"
      },
      {
        "id": "101",
        "name": "Person4",
        "number": "+91-8980439023",
        "parent": "105"
      },
      {
        "id": "110",
        "name": "Person5",
        "number": "+91-8980439023"
      },
      {
        "id": "115",
        "name": "Person6",
        "number": "+91-9834295899",
        "parent": "100"
      }
    ];
    
let hash = {};
data.forEach(d=> hash[d.parent]=d);
let parents = data.filter(d=> d.id in hash);

console.log(parents);