使用对象

Question

我有以下对象：

let obj = {
    "productData": [{
            "id": 0,
            "daily_netProfit": 1.35208688924,
            "daily_grossProfit": 1.35448688924,
            "daily_costs": 0.0024,
            "created_at": "2018-06-18"
        },
        {
            "id": 1,
            "daily_netProfit": 1.35208688924,
            "daily_grossProfit": 1.35448688924,
            "daily_costs": 0.0024,
            "created_at": "2018-06-19"
        }
    ]
}

let dataSet = obj.productData.map((item, i) => [
    item.daily_netProfit,
    item.daily_grossProfit,
    item.daily_costs,
    item.created_at,
])

console.log(dataSet)

如您所见，上面的map函数构造了一个数组中的数组。但是，带有对象的最终结果数组应如下所示：

[{
        daily_netProfit: 1.35208688924,
        daily_grossProfit: 1.35448688924,
        daily_costs: 0.0024,
        day: "2018-06-18"
    },
    {
        daily_netProfit: 1.35208688924,
        daily_grossProfit: 1.35448688924,
        daily_costs: 0.0024,
        day: "2018-06-19"
    }
],

是否有一个map函数来构造上面的array-object？

感谢您的回复！

Answer 1

您可以映射对象。

var obj = { productData: [{ id: 0, daily_netProfit: 1.35208688924, daily_grossProfit: 1.35448688924, daily_costs: 0.0024, created_at: "2018-06-18" }, { id: 1, daily_netProfit: 1.35208688924, daily_grossProfit: 1.35448688924, daily_costs: 0.0024, created_at: "2018-06-19" }] },
    dataSet = obj.productData.map(
        ({ daily_netProfit, daily_grossProfit, daily_costs, created_at: day }) =>
            ({ daily_netProfit, daily_grossProfit, daily_costs, day }))

console.log(dataSet)

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使用对象的rest语法（对于最新的JS）甚至更短

var obj = { productData: [{ id: 0, daily_netProfit: 1.35208688924, daily_grossProfit: 1.35448688924, daily_costs: 0.0024, created_at: "2018-06-18" }, { id: 1, daily_netProfit: 1.35208688924, daily_grossProfit: 1.35448688924, daily_costs: 0.0024, created_at: "2018-06-19" }] },
    dataSet = obj.productData.map(({ id, created_at: day, ...rest }) => ({ ...rest, day }));

console.log(dataSet);

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Answer 2

您正在创建数组而不是对象。改为创建对象。您可以使用参数解构来挑选所需的部件，然后使用对象初始化器来创建新对象：

＆＃13;

＆＃13;

let obj = {
  "productData": [{
      "id": 0,
      "daily_netProfit": 1.35208688924,
      "daily_grossProfit": 1.35448688924,
      "daily_costs": 0.0024,
      "created_at": "2018-06-18"
    },
    {
      "id": 1,
      "daily_netProfit": 1.35208688924,
      "daily_grossProfit": 1.35448688924,
      "daily_costs": 0.0024,
      "created_at": "2018-06-19"
    }
  ]
};

let dataSet = obj.productData.map(
  ({
    daily_netProfit,
    daily_grossProfit,
    daily_costs,
    created_at
  }) => ({
    daily_netProfit,
    daily_grossProfit,
    daily_costs,
    created_at
  })
);

console.log(dataSet)

＆＃13;

.as-console-wrapper {
  max-height: 100% !important;
}

＆＃13;

＆＃13;

＆＃13;