迭代对象数组以合并新对象

时间:2019-08-07 03:18:57

标签: javascript angular typescript lodash

我正在尝试使用数组创建新对象。我已经使用lodash贴图尝试过。但是我的问题是如何获取特定集合中的product_ids并将其放入数组中。

这是对象

[
  [
    {
      "id": "b7079be6-c9ab-4d24-9a1d-38eddde926c2",
      "collection": "mortgages",
      "product_id": "854174665132787596022"
    },
    {
      "id": "0da12779-6fe9-45d5-afbf-91d2466e5b7e",
      "collection": "mortgages",
      "product_id": "304285269353822734222"
    },
    {
      "id": "87a137ba-5f66-4e94-8d5d-698dfbaa08ec",
      "collection": "mortgages",
      "product_id": "-304414504724243127922"
    }
  ],
  [
    {
      "id": "522f4b83-4c5a-4ffe-836d-33a51325d251",
      "collection": "carinsurance",
      "product_id": "10413803"
    },
    {
      "id": "02b79566-9cf7-48fa-a8d3-eecf951b5a76",
      "collection": "carinsurance",
      "product_id": "10397803"
    }
  ]
]

我已经尝试过此代码

map(this.products, (item, key) => {
   this.arr.push({
      collection: item[0].collection,
      product_ids: item.product_id
   });
});

我想要这样的结果。

{
    "collection": "mortgages",
    "product_ids": [
        "304285269353822734222",
        "854174665132787596022",
        "-304414504724243127922"
    ]
},
{
    "collection": "carinsurance",
    "product_ids": [
        "10413803",
        "10397803"
    ]
}

但是我得到了这个结果。有人可以帮我吗?

{
    "collection": "mortgages",
    "product_ids": undefined
},
{
    "collection": "carinsurance",
    "product_ids": undefined
}

2 个答案:

答案 0 :(得分:4)

在您的情况下,

item是一个数组,但是您就像在数组本身上有一个product_id字段一样访问它,因此必须映射所有product_id属性数组中的每个项目:

map(this.products, (item, key) => {
   return {
      collection: item[0].collection,
      product_ids: item.map(i => i.product_id)
   };
});

此外,如果map函数返回一个数组,则对于初始数组中的每个项目,它都会将其转换为新格式,因此您可以返回并分配给this.arr而不是在其中推入this.arr地图功能。

答案 1 :(得分:0)

您可以使用嵌套的reduce函数。

const collect = data => data.reduce((results, item) => {
  item.reduce((results, subItem) => {
    const current = results.find(i => i.collection === subItem.collection);
    if (current) {
      current.product_ids.push(subItem.product_id);
    } else {
      results.push({ collection: subItem.collection, product_ids: [subItem.product_id] });
    }
    return results;
  }, results);
  return results;
}, []);

const data = [
  [
    {
      "id": "b7079be6-c9ab-4d24-9a1d-38eddde926c2",
      "collection": "mortgages",
      "product_id": "854174665132787596022"
    },
    {
      "id": "0da12779-6fe9-45d5-afbf-91d2466e5b7e",
      "collection": "mortgages",
      "product_id": "304285269353822734222"
    },
    {
      "id": "87a137ba-5f66-4e94-8d5d-698dfbaa08ec",
      "collection": "mortgages",
      "product_id": "-304414504724243127922"
    }
  ],
  [
    {
      "id": "522f4b83-4c5a-4ffe-836d-33a51325d251",
      "collection": "carinsurance",
      "product_id": "10413803"
    },
    {
      "id": "02b79566-9cf7-48fa-a8d3-eecf951b5a76",
      "collection": "carinsurance",
      "product_id": "10397803"
    }
  ]
];

console.log(collect(data));