javascript - 在 Javascript 中更改 JSON 对象格式

Question

我有以下 JSON 对象，它来自数据库，格式如下:

{
    "total_count": 4,
    "items": [
        {
            "id": "906a1409-b66a-4f8f-b76b-36898828faf2",
            "en": "Grade 1B",
            "de": "xyz"
        },
        {
            "id": "00ace4db-d29e-4cf4-b25c-f85369db345e",
            "en": "Grade 1A",
            "de": "xyz"
        },
        {
            "id": "6b4a5578-4f27-4370-9320-a7f57a6c0f54",
            "en": "Grade 2A",
            "de": "xyz"
        },
        {
            "id": "53b52ee8-dc2e-4c6b-8017-c913d334d5af",
            "en": "Grade 2B",
            "de": "xyz
        }
    ]
}

但我需要以下格式来使用我的 UI:

{
    "total_count": 4,
    "items": [
        {
            "id": "906a1409-b66a-4f8f-b76b-36898828faf2",
            "lang": {
                 "en": "Grade 1B",
                 "de": "xyz"
            }
        },
        {
            "id": "00ace4db-d29e-4cf4-b25c-f85369db345e",
            "lang": {
                "en": "Grade 1A",
                "de": "xyz"
             }
        },
        {
            "id": "6b4a5578-4f27-4370-9320-a7f57a6c0f54",
            "lang": {
                "en": "Grade 2A",
                "de": "xyz"
            }
        },
        {
            "id": "53b52ee8-dc2e-4c6b-8017-c913d334d5af",
            "lang": {
                 "en": "Grade 2B"
                 "de": "xyz"
        }
    ]
}

是否有一种简单的 javascript 方法来执行此转换？也许是 map 方法？

我正在尝试这样的事情:

var rows_Original; // this comes from DB
var rows_Result= {}; // new json

rows_Result["total_count"] = rows_Original.length;
rows_Result['items']  = rows_Original;
rows_Result['items'].lang={};
for (var item in rows_Result['items']) {
      item[i].lang.en  = item.en;
      item[i].lang.de = 'item.de;
}

但我一直在获取像 de、en 这样的元素(无法设置未定义的属性“en”)

感谢和问候

Answer 1

你可以 destructure id 并获取 rest lang 变量的属性。然后使用 Shorthand property names使用嵌套的 lang 属性创建新对象

const input = {total_count:4,items:[{id:"906a1409-b66a-4f8f-b76b-36898828faf2",en:"Grade 1B",de:"xyz"},{id:"00ace4db-d29e-4cf4-b25c-f85369db345e",en:"Grade 1A",de:"xyz"},{id:"6b4a5578-4f27-4370-9320-a7f57a6c0f54",en:"Grade 2A",de:"xyz"},{id:"53b52ee8-dc2e-4c6b-8017-c913d334d5af",en:"Grade 2B",de:"xyz"}]};

const { total_count, items } = input;

const newItems = items.map(({ id, ...lang }) => ({ id, lang }) ),
      output = { total_count, items: newItems };

console.log(output)

如果不支持解构和剩余语法，您可以像这样遍历每个项目的键:

var input = {total_count:4,items:[{id:"906a1409-b66a-4f8f-b76b-36898828faf2",en:"Grade 1B",de:"xyz"},{id:"00ace4db-d29e-4cf4-b25c-f85369db345e",en:"Grade 1A",de:"xyz"},{id:"6b4a5578-4f27-4370-9320-a7f57a6c0f54",en:"Grade 2A",de:"xyz"},{id:"53b52ee8-dc2e-4c6b-8017-c913d334d5af",en:"Grade 2B",de:"xyz"}]};

var output = {
  total_count: input.total_count,
  items: []
};

for (var item of input.items) {
  var newItem = {};

  for (var key in item) {
    if (key === 'id')
      newItem[key] = item[key]
    else {
      newItem.lang = newItem.lang || {};
      newItem.lang[key] = item[key]
    }
  }
  
  output.items.push(newItem)
}

console.log(output)