javascript - javascript中的数据转换

Question

我将以下类型的数据分配给 var dataTransformation ，我使用度量标准从 apache 超集中的用户那里获取。

{country: "Afghanistan", region: "South Asia", year: 1960, value: 91.779}
{country: "Afghanistan", region: "South Asia", year: 1961, value: 91.492}
{country: "Afghanistan", region: "South Asia", year: 1962, value: 91.195}
{country: "Bangladesh", region: "South Asia", year: 1960, value: 94.865}
{country: "Bangladesh", region: "South Asia", year: 1961, value: 94.722}
{country: "Bangladesh", region: "South Asia", year: 1962, value: 94.502}
{country: "Canada", region: "North America", year: 1960, value: 30.939}
{country: "Canada", region: "North America", year: 1961, value: 30.332}
{country: "Canada", region: "North America", year: 1962, value: 29.506}

但我想将其转换为以下格式。我尝试使用数组映射函数、循环和字符串连接，但效率不高。有没有办法在javascript中做到这一点？

{
   "South Asia": [
      ["Afghanistan", 91.779, 91.492, 91.195],
      ["Bangladesh", 94.865, 94.722, 94.502],
   ],
   "North America":[
      ["Canada", 30.939, 30.332, 29.506],
    ],
}

我期待一个关于如何做到这一点的指南，而不是完全工作的代码。

Answer 1

const data = [{
  country: "Afghanistan",
  region: "South Asia",
  year: 1960,
  value: 91.779
},{
  country: "Afghanistan",
  region: "South Asia",
  year: 1961,
  value: 91.492
},{
  country: "Afghanistan",
  region: "South Asia",
  year: 1962,
  value: 91.195
},{
  country: "Bangladesh",
  region: "South Asia",
  year: 1960,
  value: 94.865
},{
  country: "Bangladesh",
  region: "South Asia",
  year: 1961,
  value: 94.722
},{
  country: "Bangladesh",
  region: "South Asia",
  year: 1962,
  value: 94.502
},{
  country: "Canada",
  region: "North America",
  year: 1960,
  value: 30.939
},{
  country: "Canada",
  region: "North America",
  year: 1961,
  value: 30.332
},{
  country: "Canada",
  region: "North America",
  year: 1962,
  value: 29.506
}];

const res = data.reduce((acc, {country, region, year, value}) => {
  acc = {
    ...acc,
    [region]: {
      ...acc[region],
      [country]: !acc?.[region]?.[country] ? [value] : acc[region][country].concat(value) 
    }
  }
  return acc;
}, { });

console.log(res);