javascript - 分组依据、不同计数、JavaScript 数组中对象的总计

Question

这可能是补救措施，但我无法弄清楚。我试过使用 d3 并使用 lodash 来获得有效的解决方案，但没有得到任何结果。

我在 JavaScript 中有一个对象数组。如果 [Selected] 值为 true，我想创建一个按 [Version Name] 分组的对象，其中包含 distinct 区域的计数，以及每个版本的总和。例如对象...

[ 
     { Selcted: false, Version Name: "aaa", Zone: "11111", Value: 5 },
     { Selcted: false, Version Name: "aaa", Zone: "11111", Value: 10 },
     { Selcted: true, Version Name: "aaa", Zone: "11111", Value: 15 },
     { Selcted: true, Version Name: "aaa", Zone: "11111", Value: 20 },
     { Selcted: true, Version Name: "aaa", Zone: "22222", Value: 25 },
     { Selcted: true, Version Name: "bbb", Zone: "22222", Value: 30 },
     { Selcted: true, Version Name: "bbb", Zone: "22222", Value: 35 },
     { Selcted: true, Version Name: "bbb", Zone: "2222", Value: 40 }
]

应该返回结果

[ 
     { Version Name: "aaa", Zone Count: "2", Value Sum: 50 },
     { Version Name: "bbb", Zone Count: "1", Value Sum: 105 },
]

Answer 1

这使用了我最喜欢的 groupBy 函数 :) 一旦你获得了组，你就可以做另一个组来获得区域计数，并进行 reduce 来获得你的总和。

简而言之

const byName = groupBy(input.filter(it => it.Selcted), it => it['Version Name'])

const output = Object.keys(byName).map(name => {
  const byZone = groupBy(byName[name], it => it.Zone)
  const sum = byName[name].reduce((acc, it) => acc + it.Value, 0)
  return {
    'Version Name': name,
    ZoneCount: Object.keys(byZone).length,
    ValueSum: sum
  }
})

不要忘记，您需要在“版本名称”周围加上引号才能将其用作 key 。

这是您的数据集的工作示例。

function groupBy(a, keyFunction) {
  const groups = {};
  a.forEach(function(el) {
    const key = keyFunction(el);
    if (key in groups === false) {
      groups[key] = [];
    }
    groups[key].push(el);
  });
  return groups;
}

const input = [{
    Selcted: false,
    'Version Name': "aaa",
    Zone: "11111",
    Value: 5
  },
  {
    Selcted: false,
    'Version Name': "aaa",
    Zone: "11111",
    Value: 10
  },
  {
    Selcted: true,
    'Version Name': "aaa",
    Zone: "11111",
    Value: 15
  },
  {
    Selcted: true,
    'Version Name': "aaa",
    Zone: "11111",
    Value: 20
  },
  {
    Selcted: true,
    'Version Name': "aaa",
    Zone: "22222",
    Value: 25
  },
  {
    Selcted: true,
    'Version Name': "bbb",
    Zone: "22222",
    Value: 30
  },
  {
    Selcted: true,
    'Version Name': "bbb",
    Zone: "22222",
    Value: 35
  },
  {
    Selcted: true,
    'Version Name': "bbb",
    Zone: "2222",
    Value: 40
  }
]

const byName = groupBy(input.filter(it => it.Selcted), it => it['Version Name'])

const output = Object.keys(byName).map(name => {
  const byZone = groupBy(byName[name], it => it.Zone)
  const sum = byName[name].reduce((acc, it) => acc + it.Value, 0)
  return {
    'Version Name': name,
    ZoneCount: Object.keys(byZone).length,
    ValueSum: sum
  }
})


console.log(output)