在JavaScript中的对象嵌套数组中查找百分比值

Question

In a nested object of arrays , the percentage value should be mapped to an object which has greater count . The data object has two arrays "distinctCount" and "groupByAndCount" . The distinctCount contains an object .

     {
        "key": "total",
        "value": 7
      }

The "groupByAndCount" based on the key name the objects should be grouped and the value with highest count should be fetched and divided by value obtained in "distinctCount" and multiplied by 100 to get the percentage Example: In key "marital_status" the "Single" value has the highest count "6" compared to the value "Married" which has low count "1"

       {
          "key": "marital_status",
          "value": "Single",
          "count": 6/7*100 = 85.7%
        }

I am a beginner in reduce function , I think reducer function is required in getting the reduced object with percentage

const result = data.groupByAndCount.map(e => e.reduce((a, { key, value, count }) => 
(a['key'] = key,a['value'] = value,a['count'] = count, a), {}));

const data = {
    distinctCount : [
      {
        "key": "total",
        "value": 7
      },
      {
        "key": "member_total",
        "value": 7
      }
    ]
    ,
    groupByAndCount : [
      [
        {
          "key": "marital_status",
          "value": "Married",
          "count": 1
        },
        {
          "key": "marital_status",
          "value": "Single",
          "count": 6
        }
      ],
      [
        {
          "key": "payment",
          "value": "POST",
          "count": 7
        }
      ],
      [
        {
          "key": "customer_code",
          "value": "ABC",
          "count": 1
        },
        {
          "key": "customer_code",
          "value": "DEF",
          "count": 6
        }
      ]
    ]
};

The expected result :

const result = {
    distinctCount : [
      {
        "key": "total",
        "value": 7
      },
      {
        "key": "member_total",
        "value": 7
      }
    ]
    ,
    groupByAndCount : [
      [
        {
          "key": "marital_status",
          "value": "Single",
          "count": 85.71
        }
      ],
      [
        {
          "key": "payment",
          "value": "POST",
          "count": 100
        }
      ],
      [
        {
          "key": "customer_code",
          "value": "DEF",
          "count": 85.71
        }
      ]
    ]
};

Answer 1

First your total count is unique so you can take it out in variable to make calculation easy. You can do that using a simple search on array of objects( data.distinctCount ).

function search(array, value){
    for (var i=0; i < array.length; i++) {
        if (array[i].key === value) { 
            return array[i].value; 
        }
    }
}

const total_value = search(data.distinctCount, 'total');

Output:
7

Second, you want object with max count from each array only(array inside data.groupByAndCount ).

const maxGroupByAndCount = data.groupByAndCount.map(function(arr){
                               return [arr.sort((a,b)=>b.count-a.count)[0]];
                           });

Output:
[
    [{key: "marital_status", value: "Single", count: 6}],
    [{key: "payment", value: "POST", count: 7}],
    [{key: "customer_code", value: "DEF", count: 6}]
]

Now, just convert each count in percentage by comparing with total_value ;

maxGroupByAndCount.map(function(arr){
  arr[0].count = (arr[0].count/ total_value) * 100;
});

console.log(maxGroupByAndCount);

Output:
[
   [{key: "marital_status", value: "Single", count: 85.71428571428571}],
   [{key: "payment", value: "POST", count: 100}],
   [{key: "customer_code", value: "DEF", count: 85.71428571428571}]
]

Now you can do object assign to make it one.

const result = { 
                  'distinctCount' : data.distinctCount, 
                  'groupByAndCount': maxGroupByAndCount
               };

You can definitely improve my answer to make it more optimized.