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javascript - 在javascript中对数组进行排序和操作

问题描述

我有以下数组：

var curr = [{ "Year": 2019, "Title": "Asset Management Sample", "Sum": 1020000.0, "Budget":0

}, {
  "Year": 2019,
  "Title": "Monday test 2",
  "Sum": 2546658.0,
  "Budget":100
}, {
  "Year": 2020,
  "Title": "Asset Management Sample",
  "Sum": 1020000.0,
  "Budget":1000
}, {
  "Year": 2020,
  "Title": "Monday test 2",
  "Sum": 3472000.0,
  "Budget":100
}, {
  "Year": 2021,
  "Title": "Asset Management Sample",
  "Sum": 1020000.0,
  "Budget":100
}, {
  "Year": 2021,
  "Title": "Monday test 2",
  "Sum": 2452000.0,
  "Budget":100
}]

我需要更改为：

[{
  "Year": 2019,
  "Asset Management Sample": 1020000.0,
  "Monday test": 2546658.0
}, {
  "Year": 2020,
  "Asset Management Sample": 1020000.0,
  "Monday test 2": 3472000.0
}, {
  "Year": 2021,
  "Asset Management Sample": 1020000.0,
  "Monday test 2": 2452000.0
}]

在早期海报的帮助下，我使用了 .reduce （从下面稍微修改）来生成这个：

      var res = arr.reduce(function(acc, curr) {
      acc[curr.Year] = acc[curr.Year];
      acc[curr.Year] = acc[curr.Year] || { Year: curr.Year } ;
      acc[curr.Year][curr.Title] = curr.Sum;

      return acc;

我需要将其扩展为包括每年所有预算值的总和（每年应该有一个预算值）。我在返回之前添加了以下行：

acc[curr.Year][curr.Budget] = curr[curr.Budget] || { Budget: curr.Budget } ;

它正在为每个预算值添加单独的条目。如何在不影响其他返回数组的情况下对预算值求和并返回它？

标签： javascriptarraysobject

解决方案

reduce像这样使用：

const arr = [{"Year":2019,"Title":"Asset Management Sample","Sum":1020000},{"Year":2019,"Title":"Monday test 2","Sum":2546658},{"Year":2020,"Title":"Asset Management Sample","Sum":1020000},{"Year":2020,"Title":"Monday test 2","Sum":3472000},{"Year":2021,"Title":"Asset Management Sample","Sum":1020000},{"Year":2021,"Title":"Monday test 2","Sum":2452000}];
const res = Object.values(arr.reduce((acc, { Year, Title, Sum }) => (acc[Year] = acc[Year] || { Year }, acc[Year][Title] = Sum, acc), {}));
console.log(res);

更详细的版本：

const arr = [{"Year":2019,"Title":"Asset Management Sample","Sum":1020000},{"Year":2019,"Title":"Monday test 2","Sum":2546658},{"Year":2020,"Title":"Asset Management Sample","Sum":1020000},{"Year":2020,"Title":"Monday test 2","Sum":3472000},{"Year":2021,"Title":"Asset Management Sample","Sum":1020000},{"Year":2021,"Title":"Monday test 2","Sum":2452000}];
const res = Object.values(arr.reduce((acc, { Year, Title, Sum }) => {
  acc[Year] = acc[Year] || { Year };
  acc[Year][Title] = Sum;
  return acc;
}, {}));
console.log(res);
.as-console-wrapper { max-height: 100% !important; top: auto; }

ES5 语法：

var arr = [{"Year":2019,"Title":"Asset Management Sample","Sum":1020000},{"Year":2019,"Title":"Monday test 2","Sum":2546658},{"Year":2020,"Title":"Asset Management Sample","Sum":1020000},{"Year":2020,"Title":"Monday test 2","Sum":3472000},{"Year":2021,"Title":"Asset Management Sample","Sum":1020000},{"Year":2021,"Title":"Monday test 2","Sum":2452000}];
var res = arr.reduce(function(acc, curr) {
  acc[curr.Year] = acc[curr.Year] || { Year: curr.Year };
  acc[curr.Year][curr.Title] = curr.Sum;
  return acc;
}, {});
res = Object.keys(res).map(function(key) {
  return res[key];
});
console.log(res);
.as-console-wrapper { max-height: 100% !important; top: auto; }

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