映射鍵值以使用javascript創建帶有嵌套物件的json結構

我想從我將從查詢結果中獲得的平面陣列創建一個陣列物件，并希望創建 json 結構作為回應以將其作為 api 回應傳遞。例如-平面陣列-

[{
    user_id: '2311123',
    user_country: 'United States',
    user_city: 'ny',
    ssn: 229
  },
  {
    user_id: '451313',
    user_country: 'United States',
    user_city: 'abc',
    ssn: 147
  },
  {
    user_id: '65345',
    user_country: 'United States',
    user_city: 'abc',
    ssn: 444
  },
  {
     user_id: '763343',
    user_country: 'Australia',
    user_city: 'auus',
    ssn: 678
  }]

我想創建一個類似于預期輸出的結構

{
  "United States": [
    {
      "ny": [
        {
          "user_id": "2311123",
          "ssn": "7"
        }
      ]
    },
    {
      "abc": [
        {
          "user_id": "451313",
          "ssn": "147"
        },
        {
          "user_id": "65345",
          "ssn": "444"
        }
      ]
    }
  ],
  "Australia": [
    {
      "auus": [
        {
          "user_id": "763343",
          "ssn": "678"
        }
      ]
    }
  ]
}

其中映射了 user_country 物件陣列和 user_city 物件陣列。我試過這段代碼，但沒有達到預期的輸出。：

  const map = {};
  results.forEach(arr => {
   console.log("arr",arr)
        if(map[arr.user_country]){
          if(!map[arr.user_country].includes(arr.user_city))
            map[arr.user_country].push(arr.user_city);
        }else{
          map[arr.user_country] = [arr.user_city]
        }
  });
  console.log(map);

uj5u.com熱心網友回復：

這可能會產生預期的結果：

const array = [{ user_id: '2311123', user_country: 'United States', user_city: 'ny', ssn: 229 }, { user_id: '451313', user_country: 'United States', user_city: 'abc', ssn: 147 }, { user_id: '65345', user_country: 'United States', user_city: 'abc', ssn: 444 }, { user_id: '763343', user_country: 'Australia', user_city: 'auus', ssn: 678 }];


const map = array.reduce((map, {user_country, user_city, ...userInfo}) => {
  if (!map[user_country]) {
    map[user_country] = [{[user_city]: [{...userInfo}]}];
  } else {
    const ex = map[user_country].find(city => Object.keys(city)[0] === user_city);
    if (!ex) {
      map[user_country].push({[user_city]: [{...userInfo}]});
    } else {
      Object.values(ex)[0].push({...userInfo});
    }
  }
  return map;
}, {});

console.log(map);

uj5u.com熱心網友回復：

const results = [{
    user_id: '2311123',
    user_country: 'United States',
    user_city: 'ny',
    ssn: 229
  },
  {
    user_id: '451313',
    user_country: 'United States',
    user_city: 'abc',
    ssn: 147
  },
  {
    user_id: '65345',
    user_country: 'United States',
    user_city: 'abc',
    ssn: 444
  },
  {
    user_id: '763343',
    user_country: 'Australia',
    user_city: 'auus',
    ssn: 678
  }
]

const out = {};
results.forEach(i => {
  out[i.user_country] = out[i.user_country] || {};
  out[i.user_country][i.user_city] = out[i.user_country][i.user_city] || [];
  out[i.user_country][i.user_city].push({
    user_id: i.user_id,
    ssn: i.ssn
  })
})

console.log(out)

uj5u.com熱心網友回復：

請檢查該選項：

const results = [{
    user_id: '2311123',
    user_country: 'United States',
    user_city: 'ny',
    ssn: 229
  },
  {
    user_id: '451313',
    user_country: 'United States',
    user_city: 'abc',
    ssn: 147
  },
  {
    user_id: '65345',
    user_country: 'United States',
    user_city: 'abc',
    ssn: 444
  },
  {
     user_id: '763343',
    user_country: 'Australia',
    user_city: 'auus',
    ssn: 678
  }];

const countries = {};

results.forEach(result => {
  const {user_country, user_city, user_id, ssn} = result;
  const cityList = countries[user_country] && countries[user_country][user_city] ? countries[user_country][user_city] : [];
  const newCityList = [...cityList, {
      user_id,
      ssn
    }];
  countries[user_country] = {
    ...countries[user_country],
    [user_city]: newCityList
  };
});

console.log(countries);

uj5u.com熱心網友回復：

請檢查此解決方案：

const map = {};
results.forEach(arr => {
    const { user_country, user_id, user_city, ssn } = arr;
    if (!map[user_country]) {
        map[user_country] = [];
    }

    if (map[user_country][user_city]) {
        map[user_country][user_city].push({user_id, ssn});
    } else {
        map[user_country][user_city] = [{user_id, ssn}];
    }
});

console.log(map)

標籤：javascript 数组 json 目的 映射

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