如何使用 JavaScript 在 JSON 中查找公用名对象

Question

我正在寻找 2 小时的 JSON 逻辑，但我还没有找到任何解决方案。我的 json 数据如下所示：

[
  {
    "_id": "5ae30d020135436357a4732e",
    "balance": "1,171.56",
    "age": 46,
    "eyeColor": "hazel",
    "name": {
      "first": "Colon",
      "last": "Key"
    },
    "company": "Orbaxter",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "706 Tennis Court, Kimmell, Indiana, 4057",
    "registered": "2014-12-24T10:31:42 -00:00",
    "latitude": 22.250647,
    "longitude": -67.325278
  },
  {
    "_id": "5ae30d027f167186f52e2e6c",
    "balance": "1,383.36",
    "age": 23,
    "eyeColor": "hazel",
    "name": {
      "first": "Byrd",
      "last": "Walls"
    },
    "company": "Bizmatic",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "187 Lewis Avenue, Lutsen, Oregon, 7387",
    "registered": "2017-06-19T09:24:42 -01:00",
    "latitude": -60.642235,
    "longitude": -62.947158
  },
  {
    "_id": "5ae30d023f1f434dcb1ea87d",
    "balance": "2,338.81",
    "age": 21,
    "eyeColor": "grey",
    "name": {
      "first": "Sondra",
      "last": "Booker"
    },
    "company": "Aquazure",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "633 Billings Place, Jacumba, Louisiana, 1488",
    "registered": "2017-12-11T08:53:27 -00:00",
    "latitude": 18.681413,
    "longitude": 93.058578
  },
  {
    "_id": "5ae30d02826a978c51641cfb",
    "balance": "2,959.74",
    "age": 40,
    "eyeColor": "hazel",
    "name": {
      "first": "Tammi",
      "last": "Salazar"
    },
    "company": "Terascape",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "470 Elliott Walk, Gibbsville, New Mexico, 7298",
    "registered": "2014-08-06T09:06:17 -01:00",
    "latitude": -75.890626,
    "longitude": 19.674008
  },
  {
    "_id": "5ae30d02dd1046807a0e3636",
    "balance": "1,960.08",
    "age": 42,
    "eyeColor": "hazel",
    "name": {
      "first": "Maryellen",
      "last": "Merritt"
    },
    "company": "Digial",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "189 Jerome Street, Hoehne, Palau, 8982",
    "registered": "2017-06-18T10:16:48 -01:00",
    "latitude": -16.254906,
    "longitude": 112.500547
  },
  {
    "_id": "5ae30d02081e34940395696e",
    "balance": "3,324.41",
    "age": 49,
    "eyeColor": "brown",
    "name": {
      "first": "Liz",
      "last": "Harrell"
    },
    "company": "Codact",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "575 Waldane Court, Sussex, New Hampshire, 9982",
    "registered": "2017-01-13T10:09:11 -00:00",
    "latitude": -86.073799,
    "longitude": -48.573135
  },
  {
    "_id": "5ae30d024a9ea40d4c2ca212",
    "balance": "2,364.05",
    "age": 28,
    "eyeColor": "green",
    "name": {
      "first": "Luz",
      "last": "Sharp"
    },
    "company": "Hopeli",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "225 Huron Street, Richford, Iowa, 7066",
    "registered": "2016-09-16T08:01:17 -01:00",
    "latitude": 26.918633,
    "longitude": -24.304009
  },
  {
    "_id": "5ae30d02b08119b44fd33946",
    "balance": "2,040.30",
    "age": 21,
    "eyeColor": "blue",
    "name": {
      "first": "Celina",
      "last": "Hammond"
    },
    "company": "Digigene",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "433 Sumner Place, Wedgewood, Arizona, 6033",
    "registered": "2017-11-21T05:27:38 -00:00",
    "latitude": -21.626178,
    "longitude": -65.326728
  },
  {
    "_id": "5ae30d021508ef1683fca66d",
    "balance": "1,930.37",
    "age": 50,
    "eyeColor": "green",
    "name": {
      "first": "Alexis",
      "last": "Chan"
    },
    "company": "Concility",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "444 Anchorage Place, Dundee, Alaska, 2502",
    "registered": "2014-02-14T12:21:44 -00:00",
    "latitude": -2.539619,
    "longitude": 95.660992
  },
  {
    "_id": "5ae30d02fc383d361e1de77c",
    "balance": "1,887.65",
    "age": 35,
    "eyeColor": "grey",
    "name": {
      "first": "Jessica",
      "last": "Park"
    },
    "company": "Kangle",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "183 Mersereau Court, Hollymead, Colorado, 8797",
    "registered": "2014-01-21T09:50:45 -00:00",
    "latitude": -55.563378,
    "longitude": -17.215224
  },
  {
    "_id": "5ae30d02aec3b3758323f307",
    "balance": "2,271.43",
    "age": 44,
    "eyeColor": "blue",
    "name": {
      "first": "Sutton",
      "last": "Nixon"
    },
    "company": "Frolix",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "483 Junius Street, Corinne, Kentucky, 6142",
    "registered": "2016-02-16T07:51:36 -00:00",
    "latitude": -69.55902,
    "longitude": 49.509631
  },
  {
    "_id": "5ae30d0210036f470ba9906f",
    "balance": "2,268.91",
    "age": 46,
    "eyeColor": "green",
    "name": {
      "first": "Reba",
      "last": "Osborne"
    },
    "company": "Ovation",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "586 Beaver Street, Edenburg, Wyoming, 8712",
    "registered": "2016-03-02T06:08:48 -00:00",
    "latitude": 57.737613,
    "longitude": -49.301794
  },
  {
    "_id": "5ae30d02f2a230afbc80f82e",
    "balance": "3,633.00",
    "age": 54,
    "eyeColor": "green",
    "name": {
      "first": "Hardy",
      "last": "Cotton"
    },
    "company": "Futurize",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "923 Miami Court, Knowlton, Ohio, 4026",
    "registered": "2016-02-22T07:35:28 -00:00",
    "latitude": 84.25911,
    "longitude": 136.825862
  }
]

这确实是一个大文件，所以我粘贴了一些。如何找到所有具有共同姓氏的人(即 json 数据的通用名字(？

我在javascript中使用ajax请求。

Answer 1

您可以使用reduce()并按名称对ID进行分组，

const data = [
  {
    "_id": "5ae30d020135436357a4732e",
    "balance": "1,171.56",
    "age": 46,
    "eyeColor": "hazel",
    "name": {
      "first": "Colon",
      "last": "Key"
    },
    "company": "Orbaxter",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "706 Tennis Court, Kimmell, Indiana, 4057",
    "registered": "2014-12-24T10:31:42 -00:00",
    "latitude": 22.250647,
    "longitude": -67.325278
  },
  {
    "_id": "5ae30d027f167186f52e2e6c",
    "balance": "1,383.36",
    "age": 23,
    "eyeColor": "hazel",
    "name": {
      "first": "Colon",
      "last": "Walls"
    },
    "company": "Bizmatic",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "187 Lewis Avenue, Lutsen, Oregon, 7387",
    "registered": "2017-06-19T09:24:42 -01:00",
    "latitude": -60.642235,
    "longitude": -62.947158
  },
  {
    "_id": "5ae30d023f1f434dcb1ea87d",
    "balance": "2,338.81",
    "age": 21,
    "eyeColor": "grey",
    "name": {
      "first": "Colon",
      "last": "Booker"
    },
    "company": "Aquazure",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "633 Billings Place, Jacumba, Louisiana, 1488",
    "registered": "2017-12-11T08:53:27 -00:00",
    "latitude": 18.681413,
    "longitude": 93.058578
  },
  {
    "_id": "5ae30d02826a978c51641cfb",
    "balance": "2,959.74",
    "age": 40,
    "eyeColor": "hazel",
    "name": {
      "first": "Tammi",
      "last": "Salazar"
    },
    "company": "Terascape",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "470 Elliott Walk, Gibbsville, New Mexico, 7298",
    "registered": "2014-08-06T09:06:17 -01:00",
    "latitude": -75.890626,
    "longitude": 19.674008
  },
  {
    "_id": "5ae30d02dd1046807a0e3636",
    "balance": "1,960.08",
    "age": 42,
    "eyeColor": "hazel",
    "name": {
      "first": "Tammi",
      "last": "Merritt"
    },
    "company": "Digial",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "189 Jerome Street, Hoehne, Palau, 8982",
    "registered": "2017-06-18T10:16:48 -01:00",
    "latitude": -16.254906,
    "longitude": 112.500547
  },
  {
    "_id": "5ae30d02081e34940395696e",
    "balance": "3,324.41",
    "age": 49,
    "eyeColor": "brown",
    "name": {
      "first": "Liz",
      "last": "Harrell"
    },
    "company": "Codact",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "575 Waldane Court, Sussex, New Hampshire, 9982",
    "registered": "2017-01-13T10:09:11 -00:00",
    "latitude": -86.073799,
    "longitude": -48.573135
  },
  {
    "_id": "5ae30d024a9ea40d4c2ca212",
    "balance": "2,364.05",
    "age": 28,
    "eyeColor": "green",
    "name": {
      "first": "Luz",
      "last": "Sharp"
    },
    "company": "Hopeli",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "225 Huron Street, Richford, Iowa, 7066",
    "registered": "2016-09-16T08:01:17 -01:00",
    "latitude": 26.918633,
    "longitude": -24.304009
  },
  {
    "_id": "5ae30d02b08119b44fd33946",
    "balance": "2,040.30",
    "age": 21,
    "eyeColor": "blue",
    "name": {
      "first": "Luz",
      "last": "Hammond"
    },
    "company": "Digigene",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "433 Sumner Place, Wedgewood, Arizona, 6033",
    "registered": "2017-11-21T05:27:38 -00:00",
    "latitude": -21.626178,
    "longitude": -65.326728
  },
  {
    "_id": "5ae30d021508ef1683fca66d",
    "balance": "1,930.37",
    "age": 50,
    "eyeColor": "green",
    "name": {
      "first": "Luz",
      "last": "Chan"
    },
    "company": "Concility",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "444 Anchorage Place, Dundee, Alaska, 2502",
    "registered": "2014-02-14T12:21:44 -00:00",
    "latitude": -2.539619,
    "longitude": 95.660992
  },
  {
    "_id": "5ae30d02fc383d361e1de77c",
    "balance": "1,887.65",
    "age": 35,
    "eyeColor": "grey",
    "name": {
      "first": "Luz",
      "last": "Park"
    },
    "company": "Kangle",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "183 Mersereau Court, Hollymead, Colorado, 8797",
    "registered": "2014-01-21T09:50:45 -00:00",
    "latitude": -55.563378,
    "longitude": -17.215224
  },
  {
    "_id": "5ae30d02aec3b3758323f307",
    "balance": "2,271.43",
    "age": 44,
    "eyeColor": "blue",
    "name": {
      "first": "Sutton",
      "last": "Nixon"
    },
    "company": "Frolix",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "483 Junius Street, Corinne, Kentucky, 6142",
    "registered": "2016-02-16T07:51:36 -00:00",
    "latitude": -69.55902,
    "longitude": 49.509631
  },
  {
    "_id": "5ae30d0210036f470ba9906f",
    "balance": "2,268.91",
    "age": 46,
    "eyeColor": "green",
    "name": {
      "first": "Sutton",
      "last": "Osborne"
    },
    "company": "Ovation",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "586 Beaver Street, Edenburg, Wyoming, 8712",
    "registered": "2016-03-02T06:08:48 -00:00",
    "latitude": 57.737613,
    "longitude": -49.301794
  },
  {
    "_id": "5ae30d02f2a230afbc80f82e",
    "balance": "3,633.00",
    "age": 54,
    "eyeColor": "green",
    "name": {
      "first": "Hardy",
      "last": "Cotton"
    },
    "company": "Futurize",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "923 Miami Court, Knowlton, Ohio, 4026",
    "registered": "2016-02-22T07:35:28 -00:00",
    "latitude": 84.25911,
    "longitude": 136.825862
  },
  {
    "_id": "5ae30d02519a87f76fc8a0e6",
    "balance": "1,902.75",
    "age": 47,
    "eyeColor": "green",
    "name": {
      "first": "Ashlee",
      "last": "Gregory"
    }
  }
];
const result = data.reduce((all, curr) => {
  (all[curr.name.first] = all[curr.name.first] || []).push(
  curr["_id"]
  );
  return all;
}, {});
const formattedResult = Object.entries(result).map(([name, ids]) => ({
  name,
  ids,
  repeated : ids.length,  
}));
console.log(formattedResult);
// for top 5 repeated names : 
const topFive = formattedResult.sort((a,b) => b.repeated - a.repeated).slice(0, 5);

生成的Object将具有name作为键，并ids具有相同名称的相应值，(为了演示，我修改了第二个名称的输入(

Answer 2

如果要

收集名称，可以映射数据并提取name，然后first：

const names = data.map(item => item.name ? item.name.first : '');

如果要对具有相同名称的所有用户进行分组，请使用 reduce 。例如，要收集_id

：

const sameNames = data.reduce((accum, { name: { first }, _id }) => {
  accum[first] = [...(accum[first] || []), _id];
  return accum;
}, {});

下面是一个示例：

const data = [
  {
    "_id": "5ae30d020135436357a4732e",
    "balance": "1,171.56",
    "age": 46,
    "eyeColor": "hazel",
    "name": {
      "first": "Colon",
      "last": "Key"
    },
    "company": "Orbaxter",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "706 Tennis Court, Kimmell, Indiana, 4057",
    "registered": "2014-12-24T10:31:42 -00:00",
    "latitude": 22.250647,
    "longitude": -67.325278
  },
  {
    "_id": "5ae30d027f167186f52e2e6c",
    "balance": "1,383.36",
    "age": 23,
    "eyeColor": "hazel",
    "name": {
      "first": "Byrd",
      "last": "Walls"
    },
    "company": "Bizmatic",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "187 Lewis Avenue, Lutsen, Oregon, 7387",
    "registered": "2017-06-19T09:24:42 -01:00",
    "latitude": -60.642235,
    "longitude": -62.947158
  },
  {
    "_id": "5ae30d023f1f434dcb1ea87d",
    "balance": "2,338.81",
    "age": 21,
    "eyeColor": "grey",
    "name": {
      "first": "Colon",
      "last": "Booker"
    },
    "company": "Aquazure",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "633 Billings Place, Jacumba, Louisiana, 1488",
    "registered": "2017-12-11T08:53:27 -00:00",
    "latitude": 18.681413,
    "longitude": 93.058578
  },
  {
    "_id": "5ae30d02826a978c51641cfb",
    "balance": "2,959.74",
    "age": 40,
    "eyeColor": "hazel",
    "name": {
      "first": "Tammi",
      "last": "Salazar"
    },
    "company": "Terascape",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "470 Elliott Walk, Gibbsville, New Mexico, 7298",
    "registered": "2014-08-06T09:06:17 -01:00",
    "latitude": -75.890626,
    "longitude": 19.674008
  },
  {
    "_id": "5ae30d02dd1046807a0e3636",
    "balance": "1,960.08",
    "age": 42,
    "eyeColor": "hazel",
    "name": {
      "first": "Maryellen",
      "last": "Merritt"
    },
    "company": "Digial",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "189 Jerome Street, Hoehne, Palau, 8982",
    "registered": "2017-06-18T10:16:48 -01:00",
    "latitude": -16.254906,
    "longitude": 112.500547
  },
  {
    "_id": "5ae30d02081e34940395696e",
    "balance": "3,324.41",
    "age": 49,
    "eyeColor": "brown",
    "name": {
      "first": "Liz",
      "last": "Harrell"
    },
    "company": "Codact",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "575 Waldane Court, Sussex, New Hampshire, 9982",
    "registered": "2017-01-13T10:09:11 -00:00",
    "latitude": -86.073799,
    "longitude": -48.573135
  },
  {
    "_id": "5ae30d024a9ea40d4c2ca212",
    "balance": "2,364.05",
    "age": 28,
    "eyeColor": "green",
    "name": {
      "first": "Luz",
      "last": "Sharp"
    },
    "company": "Hopeli",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "225 Huron Street, Richford, Iowa, 7066",
    "registered": "2016-09-16T08:01:17 -01:00",
    "latitude": 26.918633,
    "longitude": -24.304009
  },
  {
    "_id": "5ae30d02b08119b44fd33946",
    "balance": "2,040.30",
    "age": 21,
    "eyeColor": "blue",
    "name": {
      "first": "Liz",
      "last": "Hammond"
    },
    "company": "Digigene",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "433 Sumner Place, Wedgewood, Arizona, 6033",
    "registered": "2017-11-21T05:27:38 -00:00",
    "latitude": -21.626178,
    "longitude": -65.326728
  },
  {
    "_id": "5ae30d021508ef1683fca66d",
    "balance": "1,930.37",
    "age": 50,
    "eyeColor": "green",
    "name": {
      "first": "Alexis",
      "last": "Chan"
    },
    "company": "Concility",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "444 Anchorage Place, Dundee, Alaska, 2502",
    "registered": "2014-02-14T12:21:44 -00:00",
    "latitude": -2.539619,
    "longitude": 95.660992
  },
  {
    "_id": "5ae30d02fc383d361e1de77c",
    "balance": "1,887.65",
    "age": 35,
    "eyeColor": "grey",
    "name": {
      "first": "Jessica",
      "last": "Park"
    },
    "company": "Kangle",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "183 Mersereau Court, Hollymead, Colorado, 8797",
    "registered": "2014-01-21T09:50:45 -00:00",
    "latitude": -55.563378,
    "longitude": -17.215224
  },
  {
    "_id": "5ae30d02aec3b3758323f307",
    "balance": "2,271.43",
    "age": 44,
    "eyeColor": "blue",
    "name": {
      "first": "Sutton",
      "last": "Nixon"
    },
    "company": "Frolix",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "483 Junius Street, Corinne, Kentucky, 6142",
    "registered": "2016-02-16T07:51:36 -00:00",
    "latitude": -69.55902,
    "longitude": 49.509631
  },
  {
    "_id": "5ae30d0210036f470ba9906f",
    "balance": "2,268.91",
    "age": 46,
    "eyeColor": "green",
    "name": {
      "first": "Reba",
      "last": "Osborne"
    },
    "company": "Ovation",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "586 Beaver Street, Edenburg, Wyoming, 8712",
    "registered": "2016-03-02T06:08:48 -00:00",
    "latitude": 57.737613,
    "longitude": -49.301794
  },
  {
    "_id": "5ae30d02f2a230afbc80f82e",
    "balance": "3,633.00",
    "age": 54,
    "eyeColor": "green",
    "name": {
      "first": "Sutton",
      "last": "Cotton"
    },
    "company": "Futurize",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "923 Miami Court, Knowlton, Ohio, 4026",
    "registered": "2016-02-22T07:35:28 -00:00",
    "latitude": 84.25911,
    "longitude": 136.825862
  },
  {
    "_id": "5ae30d02519a87f76fc8a0e6",
    "balance": "1,902.75",
    "age": 47,
    "eyeColor": "green",
    "name": {
      "first": "Ashlee",
      "last": "Gregory"
    }
  }
];
const sameNames = data.reduce((accum, { name: { first }, _id }) => {
  accum[first] = [...(accum[first] || []), _id];
  return accum;
}, {});
console.log(sameNames);

Answer 3

要按名字对用户进行分组，您可以使用 reduce 函数。这将创建一个对象，该对象以名字作为键，将用户组作为值。

• 如果名字不在最终对象中，则将其添加为键，并带有仅包含该用户的数组作为值
• 如果它已经存在，请将其追加到值

const groupUsersByFirstName = arr => arr.reduce((acc, curr) => {
  if (!(curr.name.first in acc)) {
     acc[curr.name.first] = [curr];
  } else {
     acc[curr.name.first].append(curr);
  }
  
  return acc;
}, {});
const users = [{
    "_id": "5ae30d020135436357a4732e",
    "balance": "1,171.56",
    "age": 46,
    "eyeColor": "hazel",
    "name": {
      "first": "Colon",
      "last": "Key"
    },
    "company": "Orbaxter",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "706 Tennis Court, Kimmell, Indiana, 4057",
    "registered": "2014-12-24T10:31:42 -00:00",
    "latitude": 22.250647,
    "longitude": -67.325278
  },
  {
    "_id": "5ae30d027f167186f52e2e6c",
    "balance": "1,383.36",
    "age": 23,
    "eyeColor": "hazel",
    "name": {
      "first": "Byrd",
      "last": "Walls"
    },
    "company": "Bizmatic",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "187 Lewis Avenue, Lutsen, Oregon, 7387",
    "registered": "2017-06-19T09:24:42 -01:00",
    "latitude": -60.642235,
    "longitude": -62.947158
  }, {
    "_id": "5ae30d023f1f434dcb1ea87d",
    "balance": "2,338.81",
    "age": 21,
    "eyeColor": "grey",
    "name": {
      "first": "Sondra",
      "last": "Booker"
    },
    "company": "Aquazure",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "633 Billings Place, Jacumba, Louisiana, 1488",
    "registered": "2017-12-11T08:53:27 -00:00",
    "latitude": 18.681413,
    "longitude": 93.058578
  }, {
    "_id": "5ae30d02826a978c51641cfb",
    "balance": "2,959.74",
    "age": 40,
    "eyeColor": "hazel",
    "name": {
      "first": "Tammi",
      "last": "Salazar"
    },
    "company": "Terascape",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "470 Elliott Walk, Gibbsville, New Mexico, 7298",
    "registered": "2014-08-06T09:06:17 -01:00",
    "latitude": -75.890626,
    "longitude": 19.674008
  }, {
    "_id": "5ae30d02dd1046807a0e3636",
    "balance": "1,960.08",
    "age": 42,
    "eyeColor": "hazel",
    "name": {
      "first": "Maryellen",
      "last": "Merritt"
    },
    "company": "Digial",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "189 Jerome Street, Hoehne, Palau, 8982",
    "registered": "2017-06-18T10:16:48 -01:00",
    "latitude": -16.254906,
    "longitude": 112.500547
  }, {
    "_id": "5ae30d02081e34940395696e",
    "balance": "3,324.41",
    "age": 49,
    "eyeColor": "brown",
    "name": {
      "first": "Liz",
      "last": "Harrell"
    },
    "company": "Codact",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "575 Waldane Court, Sussex, New Hampshire, 9982",
    "registered": "2017-01-13T10:09:11 -00:00",
    "latitude": -86.073799,
    "longitude": -48.573135
  }, {
    "_id": "5ae30d024a9ea40d4c2ca212",
    "balance": "2,364.05",
    "age": 28,
    "eyeColor": "green",
    "name": {
      "first": "Luz",
      "last": "Sharp"
    },
    "company": "Hopeli",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "225 Huron Street, Richford, Iowa, 7066",
    "registered": "2016-09-16T08:01:17 -01:00",
    "latitude": 26.918633,
    "longitude": -24.304009
  }, {
    "_id": "5ae30d02b08119b44fd33946",
    "balance": "2,040.30",
    "age": 21,
    "eyeColor": "blue",
    "name": {
      "first": "Celina",
      "last": "Hammond"
    },
    "company": "Digigene",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "433 Sumner Place, Wedgewood, Arizona, 6033",
    "registered": "2017-11-21T05:27:38 -00:00",
    "latitude": -21.626178,
    "longitude": -65.326728
  }, {
    "_id": "5ae30d021508ef1683fca66d",
    "balance": "1,930.37",
    "age": 50,
    "eyeColor": "green",
    "name": {
      "first": "Alexis",
      "last": "Chan"
    },
    "company": "Concility",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "444 Anchorage Place, Dundee, Alaska, 2502",
    "registered": "2014-02-14T12:21:44 -00:00",
    "latitude": -2.539619,
    "longitude": 95.660992
  }, {
    "_id": "5ae30d02fc383d361e1de77c",
    "balance": "1,887.65",
    "age": 35,
    "eyeColor": "grey",
    "name": {
      "first": "Jessica",
      "last": "Park"
    },
    "company": "Kangle",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "183 Mersereau Court, Hollymead, Colorado, 8797",
    "registered": "2014-01-21T09:50:45 -00:00",
    "latitude": -55.563378,
    "longitude": -17.215224
  }, {
    "_id": "5ae30d02aec3b3758323f307",
    "balance": "2,271.43",
    "age": 44,
    "eyeColor": "blue",
    "name": {
      "first": "Sutton",
      "last": "Nixon"
    },
    "company": "Frolix",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "483 Junius Street, Corinne, Kentucky, 6142",
    "registered": "2016-02-16T07:51:36 -00:00",
    "latitude": -69.55902,
    "longitude": 49.509631
  }, {
    "_id": "5ae30d0210036f470ba9906f",
    "balance": "2,268.91",
    "age": 46,
    "eyeColor": "green",
    "name": {
      "first": "Reba",
      "last": "Osborne"
    },
    "company": "Ovation",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "586 Beaver Street, Edenburg, Wyoming, 8712",
    "registered": "2016-03-02T06:08:48 -00:00",
    "latitude": 57.737613,
    "longitude": -49.301794
  }, {
    "_id": "5ae30d02f2a230afbc80f82e",
    "balance": "3,633.00",
    "age": 54,
    "eyeColor": "green",
    "name": {
      "first": "Hardy",
      "last": "Cotton"
    },
    "company": "Futurize",
    "email": "[e-mail]",
    "phone": "[phone]",
    "address": "923 Miami Court, Knowlton, Ohio, 4026",
    "registered": "2016-02-22T07:35:28 -00:00",
    "latitude": 84.25911,
    "longitude": 136.825862
  }, {
    "_id": "5ae30d02519a87f76fc8a0e6",
    "balance": "1,902.75",
    "age": 47,
    "eyeColor": "green",
    "name": {
      "first": "Ashlee",
      "last": "Gregory"
    }
  }
];
const grouped = groupUsersByFirstName(users);
console.log('first names', Object.keys(grouped));
console.log('grouped users', grouped);