如何获取数组中的过滤值和求和值？

Question

我有以下数组Array(   [0] => GenderEn: "Male", ProvinceEn: "Chonburi"    [1] => GenderEn: "Male", ProvinceEn: "Chonburi"    [2] => GenderEn: "Female", ProvinceEn: "Chonburi"    [3] => GenderEn: "Female", ProvinceEn: "Chonburi"    [4] => GenderEn: "Male", ProvinceEn: "BKK"    [5] => GenderEn: "Female", ProvinceEn: "BKK)然后我想从中创建这个数组：Array(   [0] => Male: "2", Female: "2" Sum : "4" Province : "Chonburi"    [1] => Male: "1", Female: "1" Sum : "2" Province : "BKK")我该怎么做？

Answer 1

您可以使用一个对象来存储信息，以省份为键。

const arr = [

  {GenderEn: "Male", ProvinceEn: "Chonburi"},

  {GenderEn: "Male", ProvinceEn: "Chonburi"},

  {GenderEn: "Female", ProvinceEn: "Chonburi"},

  {GenderEn: "Female", ProvinceEn: "Chonburi"},

  {GenderEn: "Male", ProvinceEn: "BKK"},

  {GenderEn: "Female", ProvinceEn: "BKK"}

];

var res = Object.values(

  arr.reduce((acc,{GenderEn: gender, ProvinceEn: Province})=>{

    const p = acc[Province] = acc.hasOwnProperty(Province)?acc[Province]: {Male: 0, Female: 0, Sum: 0, Province};

    p[gender]++, p.Sum++;

    return acc;

  }, {})

);

console.log(res);

Answer 2

让我们为这个分解对象括号语法和对象获取器！
由于您特别要求将数组作为输出，而不是对象：

const data = [

  {GenderEn: "Male", ProvinceEn: "Chonburi"},

  {GenderEn: "Male", ProvinceEn: "Chonburi"},

  {GenderEn: "Female", ProvinceEn: "Chonburi"},

  {GenderEn: "Female", ProvinceEn: "Chonburi"},

  {GenderEn: "Male", ProvinceEn: "BKK"},

  {GenderEn: "Female", ProvinceEn: "BKK"}

];

var output = [];

for (entry of data) {

  let el = output.find(e => e.Province == entry.ProvinceEn);

  if (el) { //If output does contain province entry, add data to it

    el[entry.GenderEn]++;

  }

  else { //Else, create it

    output.push({

      Male: entry.GenderEn == 'Male' ? 1 : 0,

      Female: entry.GenderEn == 'Female' ? 1 : 0,

      get Sum() { //If sum is a getter, you'll never have to set it manually

        return this.Male + this.Female;

      },

      Province: entry.ProvinceEn,

    });

  }

}

console.log(output);

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Answer 3

您必须首先按键对数据进行分组，在本例中为ProvinceEn。拥有组后，您可以将统计信息映射到新对象。

我提供了通用的分组和汇总功能。

const rawData = [

  { "GenderEn": "Male"   , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Male"   , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Female" , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Female" , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Male"   , "ProvinceEn": "BKK"      },

  { "GenderEn": "Female" , "ProvinceEn": "BKK"      }

]

const count = (data, key, value) =>

  data.filter(item => item[key] === value).length

const groupBy = (data, key) =>

  data.reduce((groups, item) =>

    (existingArr => ({...groups, [item[key]]: [...existingArr, item]}))

    (groups[item[key]] || []), {})

const summarize = (data, groupKey, mapper) =>

  (groups => Object.entries(groups).map(entry => mapper.apply(null, entry)))

  (groupBy(data, groupKey))

console.log(summarize(rawData, 'ProvinceEn', (key, data) => ({

  'Male'       : count(data, 'GenderEn', 'Male'),

  'Female'     : count(data, 'GenderEn', 'Female'),

  'Sum'        : data.length,

  'ProvinceEn' : key

})))

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如果上面的代码是整体式的，这就是它的样子。它非常像 LISP。;)

const rawData = [

  { "GenderEn": "Male"   , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Male"   , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Female" , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Female" , "ProvinceEn": "Chonburi" },

  { "GenderEn": "Male"   , "ProvinceEn": "BKK"      },

  { "GenderEn": "Female" , "ProvinceEn": "BKK"      }

]

const summary = (groups =>

  Object.keys(groups).map(key => ({

    'Male'       : groups[key].filter(item => item['GenderEn'] === 'Male').length,

    'Female'     : groups[key].filter(item => item['GenderEn'] === 'Female').length,

    'Sum'        : groups[key].length,

    'ProvinceEn' : key

  })))

  (rawData.reduce((groups, item) =>

    (existingArr => ({...groups, [item['ProvinceEn']]: [...existingArr, item]}))

    (groups[item['ProvinceEn']] || []), {}), 'ProvinceEn')

console.log(summary)

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Answer 4

const test = [

{GenderEn: "Male", ProvinceEn: "Chonburi"},

{GenderEn: "Male", ProvinceEn: "Chonburi"},

{GenderEn: "Female", ProvinceEn: "Chonburi"},

{GenderEn: "Female", ProvinceEn: "Chonburi"},

{GenderEn: "Male", ProvinceEn: "BKK"},

{GenderEn: "Female", ProvinceEn: "BKK"}

]

function getProvinceSum(arr){

  return arr.reduce((output, arrObj) => {

    if(!output.some(outputObj => outputObj.Province == arrObj.ProvinceEn)){

      output.push({

        Male: arrObj.GenderEn == "Male" ? 1 : 0,

        Female: arrObj.GenderEn == "Female" ? 1 : 0,

        Sum: 1,

        Province: arrObj.ProvinceEn

      });

    }else{

      const outputObj = output.find(outputObj => outputObj.Province == arrObj.ProvinceEn);

      arrObj.GenderEn == "Male" ? outputObj.Male += 1 : outputObj.Female += 1;

      outputObj.Sum += 1;

    }

    return output; 

  },[]);

}

console.log(getProvinceSum(test));