如何获取javascript对象数组中的总值

Question

我有以下数组：

[
{genderAge: "Male 25-39", count: 13029, weightedCount: 18475.6824262314, matchingSegment: 2},
{genderAge: "Female 55+", count: 35639, weightedCount: 32294.5926147014, matchingSegment: 8},
{genderAge: "Female 25-39", count: 23285, weightedCount: 20645.0599977815, matchingSegment: 6},
{genderAge: "Female 18-24", count: 7745, weightedCount: 8497.30029399032, matchingSegment: 5},
{genderAge: "Male 55+", count: 38018, weightedCount: 28589.2793936886, matchingSegment: 4},
{genderAge: "Male 18-24", count: 4038, weightedCount: 8122.65161312996, matchingSegment: 1},
{genderAge: "Female 40-54", count: 23051, weightedCount: 22834.3167597392, matchingSegment: 7},
{genderAge: "Male 40-54", count: 17278, weightedCount: 19681.8852663563, matchingSegment: 3}
]

我想将此对象数组转换为一个数组，其中包含两个对象，其中包含男性和女性的汇总数据（计数、加权计数和匹配段）。有没有使用 Lodash 和/或 ES6 实现此目的的捷径？

更新：很抱歉我提供了错误的数据。

Answer 1

function sumFor(pattern, data) {
  return data
    .filter(item => item.text.match(pattern))
    .reduce((accu, item) => accu + item.total, 0);
}
sumFor(/^Male/, data); // 125480
sumFor(/^Female/, data); // 154916

Answer 2

你可以使用reduce方法

var list = [
{genderAge: "Male 25-39", count: 13029, weightedCount: 18475.6824262314, matchingSegment: 2},
{genderAge: "Female 55+", count: 35639, weightedCount: 32294.5926147014, matchingSegment: 8},
{genderAge: "Female 25-39", count: 23285, weightedCount: 20645.0599977815, matchingSegment: 6},
{genderAge: "Female 18-24", count: 7745, weightedCount: 8497.30029399032, matchingSegment: 5},
{genderAge: "Male 55+", count: 38018, weightedCount: 28589.2793936886, matchingSegment: 4},
{genderAge: "Male 18-24", count: 4038, weightedCount: 8122.65161312996, matchingSegment: 1},
{genderAge: "Female 40-54", count: 23051, weightedCount: 22834.3167597392, matchingSegment: 7},
{genderAge: "Male 40-54", count: 17278, weightedCount: 19681.8852663563, matchingSegment: 3}
]

list.reduce(function(a, b) {
     if(/^Male/.test(b['genderAge'])) {
        a['male']['pop'] += b['count'];
        a['male']['matchingSegment'] += b['matchingSegment'];
        a['male']['weightedCount'] += b['weightedCount'];
    } else if(/^Female/.test(b['genderAge'])){
        a['female']['pop'] += b['count'];
        a['female']['matchingSegment'] += b['matchingSegment'];
        a['female']['weightedCount'] += b['weightedCount'];
    }
     return a;
}, {'male':{'pop':0, 'matchingSegment':0, 'weightedCount':0}, 'female':{'pop':0, 'matchingSegment':0, 'weightedCount':0}});

Answer 3

您可以按想要的值分组并获得total 的总和。

var data = array = [{ text: "Male 18-24 (12886)", value: "test_1", total: 12886 }, { text: "Male 25-39 (27913)", value: "test_2", total: 27913 }, { text: "Male 40-54 (29793)", value: "test__3", total: 29793 }, { text: "Male 55+ (54888)", value: "test__4", total: 54888 }, { text: "Female 18-24 (19354)", value: "test_5", total: 19354 }, { text: "Female 25-39 (43972)", value: "test_6", total: 43972 }, { text: "Female 40-54 (39327)", value: "test_7", total: 39327 }, { text: "Female 55+ (52263)", value: "test_8", total: 52263 }],
    result = _(data)
        .groupBy(o => o.text.match(/^\S+/)[0])
        .map((array, group) => ({ group, sum: _.sumBy(array, 'total') }))
        .value();

    console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>

Answer 4

const { Sum, mreduceMap, compose, propOr, ifElse, constant } = crocks

const data = [
  {text: "Male 18-24 (12886)", value: "test_1", total: 12886},
  {text: "Male 25-39 (27913)", value: "test_2", total: 27913},
  {text: "Male 40-54 (29793)", value: "test__3", total: 29793},
  {text: "Male 55+ (54888)", value: "test__4", total: 54888},
  {text: "Female 18-24 (19354)", value: "test_5", total: 19354},
  {text: "Female 25-39 (43972)", value: "test_6", total: 43972},
  {text: "Female 40-54 (39327)", value: "test_7", total: 39327},
  {text: "Female 55+ (52263)", value: "test_8", total: 52263}
]

const startsWith = x => str =>
  typeof str === 'string' &&
  str.startsWith(x)

const isSex = sex =>
  compose(startsWith(sex), propOr('', 'text'))

const totalFor = sex =>
  ifElse(isSex(sex), propOr(0, 'total'), constant(0))

const sumSex = sex =>
  mreduceMap(Sum, totalFor(sex))

const sumMales = sumSex('Male')
const sumFemales = sumSex('Female')

const males = sumMales(data)
const females = sumFemales(data)

console.log({males, females})

<script src="https://unpkg.com/crocks@0.10.1/dist/crocks.min.js"></script>

使用crocks 库，您可以使用功能强大的方法来解决问题。

Answer 5

ES6

.reduce((acc,e)=>{
  if (/^Male/.test(e.text)){
   acc[0].total+=e.total
  }
  if (/^Female/.test(e.text)){
   acc[1].total+=e.total
  }
  return acc
},[{total:0},{total:0}])

Answer 6

您可以简单地用两个objects 初始化array，第一个用于Male，第二个用于Female。

let result = [{text: "Male", total:0}, {text: "Female", total:0}];

然后使用forEach 循环在您的第一个array 上填充相关数据。

array.forEach(function(a){
   if(a.genderAge.indexOf("Male")>-1){
      result[0].total += a.count;
   }else if(a.genderAge.indexOf("Female")>-1){
      result[1].total += a.count;
   }
});

演示：

var array = [
{genderAge: "Male 25-39", count: 13029, weightedCount: 18475.6824262314, matchingSegment: 2},
{genderAge: "Female 55+", count: 35639, weightedCount: 32294.5926147014, matchingSegment: 8},
{genderAge: "Female 25-39", count: 23285, weightedCount: 20645.0599977815, matchingSegment: 6},
{genderAge: "Female 18-24", count: 7745, weightedCount: 8497.30029399032, matchingSegment: 5},
{genderAge: "Male 55+", count: 38018, weightedCount: 28589.2793936886, matchingSegment: 4},
{genderAge: "Male 18-24", count: 4038, weightedCount: 8122.65161312996, matchingSegment: 1},
{genderAge: "Female 40-54", count: 23051, weightedCount: 22834.3167597392, matchingSegment: 7},
{genderAge: "Male 40-54", count: 17278, weightedCount: 19681.8852663563, matchingSegment: 3}
];

let result = [{text: "Male", total:0}, {text: "Female", total:0}];

array.forEach(function(a){
   if(a.genderAge.indexOf("Male")>-1){
      result[0].total += a.count;
   }else if(a.genderAge.indexOf("Female")>-1){
      result[1].total += a.count;
   }
});

console.log(result);

Answer 7

这是另一种简单的 lodash 方法，它使用 _.groupBy 并且只执行一个循环：

var data = [ {genderAge: "Male 25-39", count: 13029, weightedCount: 18475.6824262314, matchingSegment: 2}, {genderAge: "Female 55+", count: 35639, weightedCount: 32294.5926147014, matchingSegment: 8}, {genderAge: "Female 25-39", count: 23285, weightedCount: 20645.0599977815, matchingSegment: 6}, {genderAge: "Female 18-24", count: 7745, weightedCount: 8497.30029399032, matchingSegment: 5}, {genderAge: "Male 55+", count: 38018, weightedCount: 28589.2793936886, matchingSegment: 4}, {genderAge: "Male 18-24", count: 4038, weightedCount: 8122.65161312996, matchingSegment: 1}, {genderAge: "Female 40-54", count: 23051, weightedCount: 22834.3167597392, matchingSegment: 7}, {genderAge: "Male 40-54", count: 17278, weightedCount: 19681.8852663563, matchingSegment: 3} ]

const getGenderTotals = data => {
   let Males = 0, Females = 0
   _.groupBy(data, (r => {/^Male/.test(r.genderAge) ? Males += r.count : Females += r.count}))
   return { Males, Females }
}

console.log(getGenderTotals(data))

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

由于我们可以访问该值并且我们在 _.groupBy 上下文中，您还可以轻松地在 groupBy iteratee 函数中返回 Male 或 Female 以获取实际的组等。