如何防止对象属性被覆盖

Question

我正在构建一个函数，该函数创建一个具有动态属性的嵌套对象，该对象以年和月为键。

const sixMonthSummary = {};
// This will get data for the latest 6 months
for (let i = 0; i <= 6; i++) {
  const currentDate = new Date();
  const [, month, year] = new Date(
    currentDate.setMonth(currentDate.getMonth() - i)
  )

    .toLocaleDateString("en-SG")
    .split("/");

  sixMonthSummary[year] = {
    [month]: {
      rent: "",
      income: "",
      expenses: "",
    },
  };
}

console.log(sixMonthSummary)

输出只捕获最后一个索引和第一个索引

"2020": {
  "07": {
      "rent": "",
      "income": "",
      "expenses": ""
  }
},
"2021": {
  "01": {
      "rent": "",
      "income": "",
      "expenses": ""
  }
}

我如何确保不会错过其他月份？

Answer 1

您正在覆盖完整的对象键

<块引用>

sixMonthSummary[年] = {}

尝试使用 spread-operator 插入现有对象以包括所有上个月。

const sixMonthSummary = {};
// This will get data for the latest 6 months
for (let i = 0; i <= 6; i++) {
  const currentDate = new Date();
  const [, month, year] = new Date(
    currentDate.setMonth(currentDate.getMonth() - i)
  )

    .toLocaleDateString("en-SG")
    .split("/");

  sixMonthSummary[year] = {
    ...sixMonthSummary[year],
    [month]: {
      rent: "",
      income: "",
      expenses: "",
    },
  };
}

console.log(sixMonthSummary)

Answer 2

这是因为您在循环的每次迭代中都重置年份键。尝试类似

if(!sixMonthSummary[year]) {
 sixMonthSummary[year] = {};
}

sixMonthSummary[year][month] = {
 rent: "",
 income: "",
 expenses: "",
};