遍歷數組內部的對象並將其求和

Question

我有一個由數據組成的數組，其中每個數據都有多個subData，

var res = [
    {
        data1:{subData1:56, subData2:0, subData3:45},
        data2:{subData2:565, subData3:67, subData4:45},
        data3:{subData1:45, subData3:0},
        data4:{subData1:32, subData2:0, subData3:47},
        data5:{subData1:107, subData2:34, subData3:65},
        data6:{subData3:123, subData4:43},
        data7:{subData1:432, subData2:67, subData3:78},
        data8:{subData4:23, subData5:432, subData6:654},

    }
  ];

我需要獲取數組中每個subDatas的總和，我已經找到了解決方案，但是如何減少代碼。 請找到以下代碼以解決問題，並提出一種更好的優化方法。 我也使用下划線js。

 var res = [ { data1:{subData1:56, subData2:0, subData3:45}, data2:{subData2:565, subData3:67, subData4:45}, data3:{subData1:45, subData3:0}, data4:{subData1:32, subData2:0, subData3:47}, data5:{subData1:107, subData2:34, subData3:65}, data6:{subData3:123, subData4:43}, data7:{subData1:432, subData2:67, subData3:78}, data8:{subData4:23, subData5:432, subData6:654}, } ]; var values = Object.values(res[0]) var arrayOfItems = []; var sums = {}; values.map(obj => Object.keys(obj)).map(item => {item.map(subItem => arrayOfItems.push(subItem))}) arrayOfItems = _.uniq(arrayOfItems) _.each(values, function (item) { _.each(arrayOfItems, function (color) { if(sums.hasOwnProperty(color)){ sums[color] = sums[color] + ( item[color] ? item[color] : 0 ) }else{ sums[color] = 0 + (item[color] ? item[color] : 0) } }); }); var arrOfSubDatasTotal = Object.keys(sums).map(item => ({name:item, total:sums[item]})) var totalOfSubDatas = Object.values(sums).reduce((a,b) => a + b) console.log("array Of SubDatas Total =>", arrOfSubDatasTotal) console.log("total Of SubDatas =>", totalOfSubDatas) 

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Answer 1

嘗試使用Array.reduce ， Array.forEach ， Array.map ， Object.values ， Object.entries

邏輯

創建一個鍵為subData{number}的對象，並將value作為其 value的總和 。

若要創建對象，請使用Array.reduce遍歷數組中的每個對象，然后使用Object.values獲取該對象中的所有值。 使用Array.forEach遍歷每個值，然后對於每個對象，使用Object.entries在中間對象中添加/更新條目（ 減少accumulator ）。

創建對象時，對所有值求和以創建所有subData's total 。 最后，使用Object.entries將object轉換為array然后使用Array.map將其轉換為所需的格式。

 var res = [{data1:{subData1:56, subData2:0, subData3:45},data2:{subData2:565, subData3:67, subData4:45},data3:{subData1:45, subData3:0},data4:{subData1:32, subData2:0, subData3:47},data5:{subData1:107, subData2:34, subData3:65},data6:{subData3:123, subData4:43},data7:{subData1:432, subData2:67, subData3:78},data8:{subData4:23, subData5:432, subData6:654}}]; let total = 0; let result = Object.entries( res.reduce((a,c) => { Object.values(c).forEach( o => Object.entries(o).forEach(([k,v]) => { a[k] = (a[k] || 0) + v; total += v; }) ); return a; }, {}) ).map(([k,v]) => ({name: k, total : v})); console.log(result); console.log(total); 

Answer 2

您可以使用Sum monoid遍歷該列表

import propOr from 'crocks/helpers/propOr'
import curry from 'crocks/helpers/curry'
import mreduceMap from 'crocks/helpers/mreduceMap'
import Sum from 'crocks/Sum'

var res = [{
  data1:{subData1:56, subData2:0, subData3:45},
  data2:{subData2:565, subData3:67, subData4:45},
  data3:{subData1:45, subData3:0},
  data4:{subData1:32, subData2:0, subData3:47},
  data5:{subData1:107, subData2:34, subData3:65},
  data6:{subData3:123, subData4:43},
  data7:{subData1:432, subData2:67, subData3:78},
  data8:{subData4:23, subData5:432, subData6:654},
}];

const data = Object.values(res[0])

const getSubData = i => propOr(0, 'subData' + i)

const getDataSum = curry(i => mreduceMap(Sum, getSubData(i)))


console.log(getDataSum(1, data))
// 672 - the sum of all subData1 properties in the list

Answer 3

您可以在純JS中嘗試。 希望能幫助到你。

 const res = [{ data1:{subData1:56, subData2:0, subData3:45}, data2:{subData2:565, subData3:67, subData4:45}, data3:{subData1:45, subData3:0}, data4:{subData1:32, subData2:0, subData3:47}, data5:{subData1:107, subData2:34, subData3:65}, data6:{subData3:123, subData4:43}, data7:{subData1:432, subData2:67, subData3:78}, data8:{subData4:23, subData5:432, subData6:654}, }]; const sums = {}; // For each item on your array res.forEach((item) => { Object.keys(item).forEach((key) => { Object.keys(item[key]).forEach((sub) => { // Initialize its position on the sum object if (!sums[sub]) sums[sub] = { sum: 0, name: sub }; sums[sub].sum += item[key][sub]; }); }); }); // Get the total of the subData const total = Object.values(sums).reduce((acc, val) => acc += val.sum, 0.0); console.log('Sums', Object.values(sums)); console.log('Total', total);