将 3 个数组转换为一个对象

Question

你好，伙计，我正在尝试将 3 个数组转换为 1 个对象。我需要每个月的数组长度与另一个数组的长度一致如果有人知道如何解决它，我将不胜感激。感谢您抽空阅读本文，祝您有愉快的一天！

数据：

const months = [
    "March 2022",
    "April 2022",
    "May 2022",
    "June 2022"
]

const values = [
    [ "-50" ],
    [ "-100",  "350", "-111" ],
    [ "201", "200" ],
    [ "-290" ]
]

const categories = [
    [ "Credit" ],
    [ "Debt", "Salary", "Credit" ],
    [ "Salary", "Salary" ],
    [ "Investments" ]
]

这是预期结果：

[
    {
        "name": "March 2022",
        "series": 
            { 
                "name": "Credit" , 
                "value": -50 
            }
        
    },
    {
        "name": "April 2022",
        "series": [
            {
                "name": "Debt",
                "value": -100
            },
            {
                "name": "Salary",
                "value": 350
            },
            {
                "name": "Credit",
                "value": -111
            }
        ]
    },
    {
        "name": "May 2022",
        "series": [
            {
                "name": "Salary",
                "value": 201
            },
            {
                "name": "Salary",
                "value": 200
            }
        ]
    },
    {
        "name": "June 2022",
        "series":
            {
                "name": "Investments",
                "value": -290
            }
        
    }
]

我最近几天所做的就是这段代码，但它不起作用，在第二个元素的长度之前它是有效的，但是，当第三个元素的长度增加时，它们开始放在一起，这还不是全部。 . 我正在使用 angular 的服务，当从 1 条路线导航到另一条路线时，它们的长度按索引 [i] 开始放样（如果通过 crtl+r 手动刷新页面它正在工作）。当第一次打电话时对于 console.log(values[i].length) 的循环，它的长度是 [1, 3, 2, 1] 这是正确的，但是在下一次调用时（在浏览页面时）长度是 [2, 6, 4 , 2] 并随着每次调用而增加：

const months = [
  "March 2022",
  "April 2022",
  "May 2022",
  "June 2022"
]

const values = [
  ["-50"],
  ["-100", "350", "-111"],
  ["201", "200"],
  ["-290"]
]

const categories = [
  ["Credit"],
  ["Debt", "Salary", "Credit"],
  ["Salary", "Salary"],
  ["Investments"]
]

let result = [];
let subArray1 = [];
let subArray2 = [];

for (let i = 0; i < values.length; i++) {

  // if 1 expense per month push to subArray1 => result
  if (values[i].length == 1) {
    subArray1.push([{
      "name": categories[i],
      "value": +values[i]
    }])
  } else {

    for (let j = 0; j < values[i].length; j++) {
      // if more then 1 expense per month push to subArray2 => subArray1 => result
      subArray2.push({
        "name": categories[i][j],
        "value": +values[i][j]
      });
    };
    subArray1.push(subArray2);
  };
};


//combine all together
for (let i = 0; i < months.length; i++) {
  result.push({
    "name": months[i],
    "series": subArray1[i]
  });
};

Answer 1

为了实现您的结果，我创建了一个构造 series 数组的函数和一个使用 series 函数的主函数。

let months = [
  "March 2022",
  "April 2022",
  "May 2022",
  "June 2022"
]

let values = [
  ["-50"],
  ["-100", "350", "-111"],
  ["201", "200"],
  ["-290"]
]

const categories = [
  ["Credit"],
  ["Debt", "Salary", "Credit"],
  ["Salary", "Salary"],
  ["Investments"]
]

const mapSeries = (index) => (values[index] || []).map((value, vindex) => ({
  name: categories[index][vindex],
  value
}))

const output = months.map((name, index) => ({
  name,
  series: mapSeries(index)
}))

console.log(output)

注：如果 values 和 categories 的每个元素数组长度不相同，那么在 mapSeries 函数中，我们可以做类似 categories[index]?.[vindex] || 'not assigned') 的操作来避免错误。

Answer 2

你就快完成了，你只需要对你的代码做一点小改动就可以了。

您需要在每次迭代时在循环内初始化 subArray2，因为我们每次都需要单独的数组。
你可以放弃 if 条件，因为无论值的数量如何，内部 for 循环都会处理它

let months = ["March 2022","April 2022","May 2022","June 2022"]
let values = [["-50"],["-100", "350", "-111"],["201", "200"],["-290"]]
const categories = [["Credit"],["Debt", "Salary", "Credit"],["Salary", "Salary"],["Investments"]]

let result = [];
let subArray1 = [];

for (let i = 0; i < values.length; i++) {
    let subArray2 = [];
    for (let j = 0; j < values[i].length; j++) {
      subArray2.push({
        "name": categories[i][j],
        "value": +values[i][j]
    });
  };
  subArray1.push(subArray2)
};

//combine all together
for (let i = 0; i < months.length; i++) {
  result.push({
    "name": months[i],
    "series": subArray1[i]
  });
};

console.log(result)

Answer 3

您可以使用嵌套的 map 生成您想要的结果，首先是 month 名称，然后是 categories，使用第二个 (index) 参数回调到 select 来自其他数组的适当值：

const months = [
  "March 2022",
  "April 2022",
  "May 2022",
  "June 2022"
]

const values = [
  ["-50"],
  ["-100", "350", "-111"],
  ["201", "200"],
  ["-290"]
]

const categories = [
  ["Credit"],
  ["Debt", "Salary", "Credit"],
  ["Salary", "Salary"],
  ["Investments"]
]

const result = months.map((m, mnum) => ({
  name: m,
  series: categories[mnum].map((c, cnum) => ({
    name: c,
    value: +values[mnum][cnum]
  }))
}))

console.log(result)

请注意，此代码总是 returns series 的数组，这似乎比试图弄清楚是数组还是对象更容易处理。

将 3 个数组转换为一个对象

Converting 3 arrays into an object

javascript

arrays

object