从嵌套的对象数组中获取总和答案

【问题标题】：Get sum from the nested array of objects从嵌套的对象数组中获取总和
【发布时间】：2021-07-21 07:40:46
【问题描述】：

我有以下对象数组。如您所见，每个对象中都有一个名为count 的嵌套对象。我想得到Closed、Verify和Analyze的总数

例如Closed 的总数为 23，Verify 为 3，Analyze 为 20

"byPerson": [
      {
        "personId": "973567318",
        "firstName": "Others",
        "lastName": "",
        "count": {
          "Closed": 7,
          "Verify": 3,
          "Analyze": 19
        }
      },
      {
        "personId": "1514903899",
        "firstName": "Yatish",
        "lastName": "Patel",
        "count": {
          "Closed": 16,
          "Analyze": 1
        }
      }
 ]

我尝试过这种方法，但没有奏效。例如获得Closed

cosnt result = data.reduce((a, b) => ({"Closed": a.count["Closed"] + b.count["Closed"]}));

【问题讨论】：

标签： javascript arrays reactjs loops object

【解决方案1】：

const byPerson = [
      {
        "personId": "973567318",
        "firstName": "Others",
        "lastName": "",
        "count": {
          "Closed": 7,
          "Verify": 3,
          "Analyze": 19
        }
      },
      {
        "personId": "1514903899",
        "firstName": "Yatish",
        "lastName": "Patel",
        "count": {
          "Closed": 16,
          "Analyze": 1
        }
      }
 ];
const sum = byPerson.reduce((agg, item) => {
  ['Closed', 'Verify', 'Analyze'].forEach(f => agg[f] += item.count[f] || 0);
  return agg;
}, {Closed: 0, Verify: 0, Analyze: 0});
console.log(sum);

【讨论】：

【解决方案2】：

使用要汇总的嵌套属性的键将数据简化为对象。在 reduce 回调中解构“totals”属性和嵌套的count 属性并计算总和。

const data = [
  {
    "personId": "973567318",
    "firstName": "Others",
    "lastName": "",
    "count": {
      "Closed": 7,
      "Verify": 3,
      "Analyze": 19
    }
  },
  {
    "personId": "1514903899",
    "firstName": "Yatish",
    "lastName": "Patel",
    "count": {
      "Closed": 16,
      "Analyze": 1
    }
  }
];

const totalCount = data.reduce(({
  Closed,
  Analyze,
  Verify
}, {
  count
}) => ({
  Closed: Closed + (count?.Closed || 0),
  Analyze: Analyze + (count?.Analyze || 0),
  Verify: Verify + (count?.Verify || 0),
}), {
  Closed: 0,
  Analyze: 0,
  Verify: 0,
});

console.log(totalCount);

【讨论】：

Resse-我运行了代码 sn-p 但它给了我错误。
@ArenTrot Ack，“整洁”按钮改变了语法。很抱歉，现在应该修复了。
Resse- 当我使用这段代码时，它告诉我 data.reduce 不是一个函数
返回 23、20、0，而不是 23、20、3
@ArenTrot 我在我的 sn-p 中将数组命名为 data，它在您的实际代码中可能有不同的名称。

【解决方案3】：

在这种情况下，您甚至不需要 reduce 并且可以使用简单的循环以及迭代 Object.keys()

const byPerson = [
      {
        "personId": "973567318",
        "firstName": "Others",
        "lastName": "",
        "count": {
          "Closed": 7,
          "Verify": 3,
          "Analyze": 19
        }
      },
      {
        "personId": "1514903899",
        "firstName": "Yatish",
        "lastName": "Patel",
        "count": {
          "Closed": 16,
          "Analyze": 1
        }
      }
 ];
 
const sum =  {Closed: 0, Verify: 0, Analyze: 0}

byPerson.forEach(({count})=> {
   Object.keys(sum).forEach(k => sum[k] += (count[k] || 0))
});
 

console.log(sum);

【讨论】：