使用Map处理JSON数据后，如何添加Catalogues标签生成目标格式？

现有如下JSON数据：

{
"siteCode": "S01",
"modelCode": "M001",
"modelDesc": "Desc01",
"price": 100,
"status": "A",
"startDate": "May  6 2023  4:13PM",
"endDate": "May  6 2023  4:13PM"
},
{
"siteCode": "S01",
"modelCode": "M001",
"modelDesc": "Desc01",
"price": 50,
"status": "A",
"startDate": "May  10 2023  4:13PM",
"endDate": "May  10 2023  4:13PM"
}

需要转换为包含Catalogues数组的目标格式：

{
  "Catalogues": [
    {
      "siteCode": "S01",
      "modelCode": "M001",
      "modelDesc": "Desc01",
      "datelist": [
        {
          "price": 100,
          "status": "A",
          "startDate": "May  6 2023  4:13PM",
          "endDate": "May  6 2023  4:13PM"
        },
        {
          "price": 50,
          "status": "A",
          "startDate": "May  10 2023  4:13PM",
          "endDate": "May  10 2023  4:13PM"
        }
      ]
    }
  ]
}

当前使用以下代码处理，但返回结果缺少外层的Catalogues标签：

const data = result.recordset

const map = new Map(data.map(({ siteCode, modelCode, modelDesc }) =>
  [modelCode, { siteCode, modelCode, modelDesc, datelist: [], }]
));
for (const { siteCode, modelCode, modelDesc, ...rest } of data) {
  map.get(modelCode).datelist.push(rest)
};
const resultMap = [...map.values()];
return res.json(resultMap)

只需要将最终的resultMap包裹在一个对象中，以Catalogues作为键即可，修改后的代码如下：

const data = result.recordset

const map = new Map(data.map(({ siteCode, modelCode, modelDesc }) =>
  [modelCode, { siteCode, modelCode, modelDesc, datelist: [], }]
));
for (const { siteCode, modelCode, modelDesc, ...rest } of data) {
  map.get(modelCode).datelist.push(rest)
};
const resultMap = [...map.values()];
// 关键修改：将结果包装成包含Catalogues键的对象
return res.json({ Catalogues: resultMap })

原理说明：

• 原代码直接返回了合并后的数组resultMap，而目标格式要求外层是一个包含Catalogues属性的对象，属性值为该数组。
• 通过{ Catalogues: resultMap }创建符合要求的结构，再传入res.json()即可生成正确的目标格式。

内容的提问来源于stack exchange，提问作者615