我有以下陣列
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作我想要的：
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”值的其他資料添加到我的 arr 陣列時，問題就出現了，例如我將它添加到我的 arr 陣列的末尾
,{
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
}]
顯然它會覆寫第一個“Total país”中的所有值，而不是用我添加的新值重復那個 agrupacion
uj5u.com熱心網友回復：
試試這個 forEach 函式：
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)
uj5u.com熱心網友回復：
將陣列縮減為一個物件，其中鍵對應于agrupacion，值對應于物件陣列。這個陣列的長度是根據一個特定的 一年出現多少次來決定的agrupacion。
因此，以下陣列：
[
{ 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 },
]
簡化為以下物件：
{
"Total país": [
{ agrupacion: "Total país", col2015: 81.8, col2016: 86.4 },
{ agrupacion: "Total país", col2015: 67.3 },
],
Oriental: [{ agrupacion: "Oriental", col2015: 78.6 }],
}
最后我們得到這個物件的值并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);轉載請註明出處，本文鏈接：https://www.uj5u.com/qukuanlian/480370.html
標籤：javascript 数组