對象數組按特定鍵對它們進行分組
[英]array of objects group them by a specific key
問題描述
我有以下數組
const arr = [{
agrupacion: "Total país",
valor: "81.8",
year: 2015
}, {
agrupacion: "Total país",
valor: "86.4",
year: 2016
}, {
agrupacion: "Total país",
valor: "67.3",
year: 2017
}, {
agrupacion: "Total país",
valor: "70.8",
year: 2018
}, {
agrupacion: "Total país",
valor: "67.6",
year: 2019
}, {
agrupacion: "Oriental",
valor: "78.6",
year: 2015
}, {
agrupacion: "Oriental",
valor: "83.1",
year: 2016
}, {
agrupacion: "Oriental",
valor: "65.6",
year: 2017
}, {
agrupacion: "Oriental",
valor: "68.1",
year: 2018
}, {
agrupacion: "Oriental",
valor: "63.7",
year: 2019
}, {
agrupacion: "Occidental",
valor: "177.3",
year: 2015
}, {
agrupacion: "Occidental",
valor: "182.9",
year: 2016
}, {
agrupacion: "Occidental",
valor: "114.3",
year: 2017
}, {
agrupacion: "Occidental",
valor: "144.5",
year: 2018
}, {
agrupacion: "Occidental",
valor: "169.9",
year: 2019
}, {
agrupacion: "Urbano",
valor: "79.6",
year: 2015
}, {
agrupacion: "Urbano",
valor: "92.5",
year: 2016
}, {
agrupacion: "Urbano",
valor: "62.1",
year: 2017
}, {
agrupacion: "Urbano",
valor: "82.2",
year: 2018
}, {
agrupacion: "Urbano",
valor: "80.6",
year: 2019
}, {
agrupacion: "Rural",
valor: "86.5",
year: 2015
}, {
agrupacion: "Rural",
valor: "63.7",
year: 2016
}, {
agrupacion: "Rural",
valor: "87.2",
year: 2017
}, {
agrupacion: "Rural",
valor: "45.7",
year: 2018
}, {
agrupacion: "Rural",
valor: "38.9",
year: 2019
}];
我使用這種方法來實現我想要的：
const groups = new Map(arr.map(({agrupacion}) => [agrupacion, { agrupacion }]));
for (const {agrupacion, valor, year} of arr) {
groups.get(agrupacion)["col" + year] = +valor;
}
const result = [...groups.values()];
輸出是（console.log（result））：
[{
agrupacion: "Total país",
col2015: 81.8,
col2016: 86.4,
col2017: 67.3,
col2018: 70.8,
col2019: 67.6
}, {
agrupacion: "Oriental",
col2015: 78.6,
col2016: 83.1,
col2017: 65.6,
col2018: 68.1,
col2019: 63.7
}, {
agrupacion: "Occidental",
col2015: 177.3,
col2016: 182.9,
col2017: 114.3,
col2018: 144.5,
col2019: 169.9
}, {
agrupacion: "Urbano",
col2015: 79.6,
col2016: 92.5,
col2017: 62.1,
col2018: 82.2,
col2019: 80.6
}, {
agrupacion: "Rural",
col2015: 86.5,
col2016: 63.7,
col2017: 87.2,
col2018: 45.7,
col2019: 38.9
}];
該輸出是我需要的格式，但是當我將具有相同“agrupacion”值的附加數據添加到我的 arr 數組時，問題就出現了，例如，我將它添加到我的 arr 數組的末尾
,{
agrupacion: "Total país",
valor: "151",
year: 2015
}, {
agrupacion: "Total país",
valor: "184",
year: 2016
}, {
agrupacion: "Total país",
valor: "165",
year: 2017
}, {
agrupacion: "Total país",
valor: "147",
year: 2018
}, {
agrupacion: "Total país",
valor: "190",
year: 2019
}
這就是我需要的：
[{
agrupacion: "Total país",
col2015: 81.8,
col2016: 86.4,
col2017: 67.3,
col2018: 70.8,
col2019: 67.6
}, {
agrupacion: "Oriental",
col2015: 78.6,
col2016: 83.1,
col2017: 65.6,
col2018: 68.1,
col2019: 63.7
}, {
agrupacion: "Occidental",
col2015: 177.3,
col2016: 182.9,
col2017: 114.3,
col2018: 144.5,
col2019: 169.9
}, {
agrupacion: "Urbano",
col2015: 79.6,
col2016: 92.5,
col2017: 62.1,
col2018: 82.2,
col2019: 80.6
}, {
agrupacion: "Rural",
col2015: 86.5,
col2016: 63.7,
col2017: 87.2,
col2018: 45.7,
col2019: 38.9
},{
agrupacion: "Total país",
col2015: 151,
col2016: 184,
col2017: 165,
col2018: 147,
col2019: 190
}];
這就是我嘗試得到的結果：
[{
agrupacion: "Total país",
col2015: 151,
col2016: 184,
col2017: 165,
col2018: 147,
col2019: 190
}, {
agrupacion: "Oriental",
col2015: 78.6,
col2016: 83.1,
col2017: 65.6,
col2018: 68.1,
col2019: 63.7
}, {
agrupacion: "Occidental",
col2015: 177.3,
col2016: 182.9,
col2017: 114.3,
col2018: 144.5,
col2019: 169.9
}, {
agrupacion: "Urbano",
col2015: 79.6,
col2016: 92.5,
col2017: 62.1,
col2018: 82.2,
col2019: 80.6
}, {
agrupacion: "Rural",
col2015: 86.5,
col2016: 63.7,
col2017: 87.2,
col2018: 45.7,
col2019: 38.9
}]
顯然它會覆蓋第一個“Total país”中的所有值，而不是用我添加的新值重復那個 agrupacion
3 個解決方案
解決方案1
2 2022-05-23 18:23:57
試試這個 forEach 函數：
let arrayBuild = []
let results = []
let currentAgrupacion = ''
let element = {}
arr.forEach(elem => {
if(currentAgrupacion !== elem.agrupacion) {
if(currentAgrupacion !== '') {
results.push(element)
}
currentAgrupacion = elem.agrupacion
element = {
agrupacion: elem.agrupacion
}
element["col"+elem.year] = parseFloat(elem.valor)
}
else {
element["col"+elem.year] = parseFloat(elem.valor)
}
})
results.push(element)
console.log(results)
解決方案2
1 已采納 2022-05-23 18:32:30
將數組縮減為一個對象，其中鍵對應於agrupacion ，值對應於對象數組。 這個數組的長度是根據一個特定的agrupacion一年出現的次數來決定的。
因此，以下數組：
[
{ agrupacion: "Total país", valor: "81.8", year: 2015 },
{ agrupacion: "Total país", valor: "86.4", year: 2016 },
{ agrupacion: "Total país", valor: "67.3", year: 2015 },
{ agrupacion: "Oriental", valor: "78.6", year: 2015 },
]
簡化為以下對象：
{
"Total país": [
{ agrupacion: "Total país", col2015: 81.8, col2016: 86.4 },
{ agrupacion: "Total país", col2015: 67.3 },
],
Oriental: [{ agrupacion: "Oriental", col2015: 78.6 }],
}
最后我們得到這個對象的值並將其展平為所需的結果。
const arr = [ { agrupacion: "Total país", valor: "81.8", year: 2015 }, { agrupacion: "Total país", valor: "86.4", year: 2016 }, { agrupacion: "Total país", valor: "67.3", year: 2017 }, { agrupacion: "Total país", valor: "70.8", year: 2018 }, { agrupacion: "Total país", valor: "67.6", year: 2019 }, { agrupacion: "Oriental", valor: "78.6", year: 2015 }, { agrupacion: "Oriental", valor: "83.1", year: 2016 }, { agrupacion: "Oriental", valor: "65.6", year: 2017 }, { agrupacion: "Oriental", valor: "68.1", year: 2018 }, { agrupacion: "Oriental", valor: "63.7", year: 2019 }, { agrupacion: "Occidental", valor: "177.3", year: 2015 }, { agrupacion: "Occidental", valor: "182.9", year: 2016 }, { agrupacion: "Occidental", valor: "114.3", year: 2017 }, { agrupacion: "Occidental", valor: "144.5", year: 2018 }, { agrupacion: "Occidental", valor: "169.9", year: 2019 }, { agrupacion: "Urbano", valor: "79.6", year: 2015 }, { agrupacion: "Urbano", valor: "92.5", year: 2016 }, { agrupacion: "Urbano", valor: "62.1", year: 2017 }, { agrupacion: "Urbano", valor: "82.2", year: 2018 }, { agrupacion: "Urbano", valor: "80.6", year: 2019 }, { agrupacion: "Rural", valor: "86.5", year: 2015 }, { agrupacion: "Rural", valor: "63.7", year: 2016 }, { agrupacion: "Rural", valor: "87.2", year: 2017 }, { agrupacion: "Rural", valor: "45.7", year: 2018 }, { agrupacion: "Rural", valor: "38.9", year: 2019 }, { agrupacion: "Total país", valor: "151", year: 2015 }, { agrupacion: "Total país", valor: "184", year: 2016 }, { agrupacion: "Total país", valor: "165", year: 2017 }, { agrupacion: "Total país", valor: "147", year: 2018 }, { agrupacion: "Total país", valor: "190", year: 2019 }, ]; const result = Object.values( arr.reduce((r, o) => { if (!r[o.agrupacion]) { r[o.agrupacion] = [{ agrupacion: o.agrupacion }]; } const item = r[o.agrupacion].find((i) => !i["col" + o.year]); if (item) { item["col" + o.year] = parseFloat(o.valor); } else { r[o.agrupacion].push({ agrupacion: o.agrupacion, ["col" + o.year]: parseFloat(o.valor), }); } return r; }, {}) ).flat(); console.log(result);
解決方案3
0 2022-05-23 19:49:29
您可以跟蹤 last yearData （您正在收集的數據組）。 如果給定的col<year>已經存在於該對象中，則創建一個新對象。
const result = [];
let yearData;
for (const {agrupacion, valor, year} of arr) {
const colYear = `col${year}`;
if (!yearData || colYear in yearData) {
yearData = { agrupacion };
result.push(yearData);
}
yearData[colYear] = +valor;
}
const arr = [ { agrupacion: "Total país", valor: "81.8", year: 2015 }, { agrupacion: "Total país", valor: "86.4", year: 2016 }, { agrupacion: "Total país", valor: "67.3", year: 2017 }, { agrupacion: "Total país", valor: "70.8", year: 2018 }, { agrupacion: "Total país", valor: "67.6", year: 2019 }, { agrupacion: "Oriental", valor: "78.6", year: 2015 }, { agrupacion: "Oriental", valor: "83.1", year: 2016 }, { agrupacion: "Oriental", valor: "65.6", year: 2017 }, { agrupacion: "Oriental", valor: "68.1", year: 2018 }, { agrupacion: "Oriental", valor: "63.7", year: 2019 }, { agrupacion: "Occidental", valor: "177.3", year: 2015 }, { agrupacion: "Occidental", valor: "182.9", year: 2016 }, { agrupacion: "Occidental", valor: "114.3", year: 2017 }, { agrupacion: "Occidental", valor: "144.5", year: 2018 }, { agrupacion: "Occidental", valor: "169.9", year: 2019 }, { agrupacion: "Urbano", valor: "79.6", year: 2015 }, { agrupacion: "Urbano", valor: "92.5", year: 2016 }, { agrupacion: "Urbano", valor: "62.1", year: 2017 }, { agrupacion: "Urbano", valor: "82.2", year: 2018 }, { agrupacion: "Urbano", valor: "80.6", year: 2019 }, { agrupacion: "Rural", valor: "86.5", year: 2015 }, { agrupacion: "Rural", valor: "63.7", year: 2016 }, { agrupacion: "Rural", valor: "87.2", year: 2017 }, { agrupacion: "Rural", valor: "45.7", year: 2018 }, { agrupacion: "Rural", valor: "38.9", year: 2019 }, { agrupacion: "Total país", valor: "151", year: 2015 }, { agrupacion: "Total país", valor: "184", year: 2016 }, { agrupacion: "Total país", valor: "165", year: 2017 }, { agrupacion: "Total país", valor: "147", year: 2018 }, { agrupacion: "Total país", valor: "190", year: 2019 }, ]; const result = []; let yearData; for (const { agrupacion, valor, year } of arr) { const colYear = `col${year}`; if (!yearData || colYear in yearData) { yearData = { agrupacion }; result.push(yearData); } yearData[colYear] = +valor; } console.log(result);
答案確實假設arr具有一定的一致性。 即每組項目共享完全相同的年份范圍（您的數據中為 2015-2019 年），並且沒有缺失年份。
產生錯誤輸出的不一致輸入的示例是：
const arr = [
{ agrupacion: "a", valor: "1", year: 2015 },
{ agrupacion: "a", valor: "2", year: 2016 },
{ agrupacion: "a", valor: "3", year: 2017 },
{ agrupacion: "b", valor: "4", year: 2015 },
// 2016 missing
{ agrupacion: "b", valor: "5", year: 2017 },
// 2015 missing
{ agrupacion: "c", valor: "6", year: 2016 },
{ agrupacion: "c", valor: "7", year: 2017 },
];
結果是：
[
{ agrupacion: "a", col2015: 1, col2016: 2, col2017: 3 },
{ agrupacion: "b", col2015: 4, col2016: 6, col2017: 5 },
{ agrupacion: "c", col2017: 7 },
]
如果可能出現這些數據空白，您需要更改：
if (!yearData || colYear in yearData)
進入：
if (!yearData || agrupacion != yearData.agrupacion || colYear in yearData)
如果agrupacion不同或col<year>已經存在，則確保使用新的yearData對象。
如何通過特定鍵在數組中按字母順序對對象進行分組？
[英]How can I group objects alphabetacally within an array by a specific key?
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