如何根据属性对象的数量增加变量

Question

我有一个部门列表，我试图计算每个部门存在多少个部门，并增加一个变量（例如i），这样我就可以在循环外调用它并将其作为每个部门的标签。

我是从这个开始的，但它不起作用：

import publicationTotal from "../data/agora-export-publicationtotal-20210803164942.json";

let stringified, myObj, subkeys;
stringified = JSON.stringify(publicationTotal);
myObj = JSON.parse(stringified);
subkeys = Object.keys(myObj[0]);

let departement= {};
let star = [];
for (let x in myObj) {
  if (Object.prototype.hasOwnProperty.call(myObj, x)) {
    for (let y in subkeys) {
      if (Object.prototype.hasOwnProperty.call(subkeys, y)) {
        if (subkeys[y] === "Departement") {
          //  star = myObj[x][subkeys[y]] + 1;
            star = departement[ myObj[x][subkeys[y]] ] = departement[ myObj[x][subkeys[y]] ] + 1;
          console.log("dept : ", star);
           
        }
      }
    }

  }
}

publicationTotal 文件包含此类信息：

[
  {
    "num_dep": "AI",
    "dep_name": "Ain",
    "region_name": "Auvergne-Rhône-Alpes",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AI",
    "dep_name": "Ain",
    "region_name": "Hauts-de-France",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AM",
    "dep_name": "Alpes-Maritimes",
    "region_name": "Auvergne-Rhône-Alpes",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AM",
    "dep_name": "Alpes-Maritimes",
    "region_name": "Provence-Alpes-Côte d'Azur",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AM",
    "dep_name": "Alpes-Maritimes",
    "region_name": "Provence-Alpes-Côte d'Azur",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AM",
    "dep_name": "Alpes-Maritimes",
    "region_name": "Provence-Alpes-Côte d'Azur",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AG",
    "dep_name": "Ariège",
    "region_name": "Auvergne-Rhône-Alpes",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AG",
    "dep_name": "Ariège",
    "region_name": "Grand Est",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AG",
    "dep_name": "Ariège",
    "region_name": "Occitanie",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AB",
    "dep_name": "Aube",
    "region_name": "Grand Est",
    "total_parrainages": 0,
    "color_dpt": ""
  },
  {
    "num_dep": "AD",
    "dep_name": "Aude",
    "region_name": "Occitanie",
    "total_parrainages": 0,
    "color_dpt": ""
  }
]

例如，i 变量将有 4 个用于“Yonne”部门，3 个用于“Val-de-Marne”部门。

预期结果是将部门名称和号码分开，这样我就可以在我想要的地方打电话给他们

Answer 1

const publicationTotal=[{Departement:"Yonne"},{Departement:"Yonne"},{Departement:"Yonne"},{Departement:"Yonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Seine-Saint-Denis"},{Departement:"Seine-Saint-Denis"},{Departement:"Seine-Saint-Denis"},{Departement:"Seine-Saint-Denis"},{Departement:"Val-de-Marne"},{Departement:"Val-de-Marne"},{Departement:"Val-de-Marne"},{Departement:"Val-d'Oise"}];

let results = {};

publicationTotal.forEach(({
  Departement
}) => {
  if (results[Departement] === undefined) {
    results[Departement] = 0
  } else {
    results[Departement] = results[Departement] + 1
  }
})

console.log(results)

Answer 2

如果部门已经退出？得到它并增加 1 否则设置 1

const departments = [{"Departement":"Yonne"},{"Departement":"Yonne"},{"Departement":"Yonne"},{"Departement":"Yonne"},{"Departement":"Essonne"},{"Departement":"Essonne"},{"Departement":"Essonne"},{"Departement":"Essonne"},{"Departement":"Essonne"},{"Departement":"Essonne"},{"Departement":"Essonne"},{"Departement":"Essonne"},{"Departement":"Seine-Saint-Denis"},{"Departement":"Seine-Saint-Denis"},{"Departement":"Seine-Saint-Denis"},{"Departement":"Seine-Saint-Denis"},{"Departement":"Val-de-Marne"},{"Departement":"Val-de-Marne"},{"Departement":"Val-de-Marne"},{"Departement":"Val-d\u0027Oise"}];

const result = departments.reduce((acc, item) => (
  acc[item['Departement']] =acc[item['Departement']]
  ?
  acc[item['Departement']] + 1
  :
  1,
  acc),{}
);

console.log(result);

// to get only department names
console.log("departments: ", Object.keys(result));

// to get only no of depatment
console.log("department values: ", Object.values(result));

Answer 3

Array.reduce 以名称为键，计数为值

const publicationTotal  = [{Departement:"Yonne"},{Departement:"Yonne"},{Departement:"Yonne"},{Departement:"Yonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Essonne"},{Departement:"Seine-Saint-Denis"},{Departement:"Seine-Saint-Denis"},{Departement:"Seine-Saint-Denis"},{Departement:"Seine-Saint-Denis"},{Departement:"Val-de-Marne"},{Departement:"Val-de-Marne"},{Departement:"Val-de-Marne"},{Departement:"Val-d'Oise"}];
const output = publicationTotal.reduce((acc, curr) => {
  acc[curr.Departement] ? acc[curr.Departement]++ : acc[curr.Departement] = 1;
  return acc;
}, {});
console.log(output);