javascript - JS : how to merge arrays with objects without duplicates

Question

let arrayFirst = [{name: 'a', num: 1}, { name: 'b', num: 1} ]
let arraySecond = [{name: 'a', num: 1}, { name: 'b', num: 1} ]
let arrayThid = [{name: 'a', num: 1}, { name: 'c', num: 1} ]

... ... ...

预期输出:

[{name: 'a', num: 3}, { name: 'b', num: 2}, { name: 'c', num: 1} ]

我只找到了数组内部对象求和，但是数组按其对象键值求和怎么样？

Answer 1

您可以使用以下函数对值进行分组和求和。该方法根据需要获取尽可能多的数组(或对象)，并根据 groupby (您的例子中的名称)和 sumkey 对它们进行求和

function sumArrays(groupby, sumkey, ...arrays) {
  return [...arrays.flat().reduce((a, b) => a.set(b[groupby], (a.get(b[groupby]) || 0) + b[sumkey]), new Map())].map(([k, v]) => ({
    [groupby]: k,
    [sumkey]: v
  }))
}

console.log(sumArrays('name', 'num', arrayFirst, arraySecond, arrayThid));

<script>
arrayFirst = [{
  name: 'a',
  num: 1
}, {
  name: 'b',
  num: 1
}]
let arraySecond = [{
  name: 'a',
  num: 1
}, {
  name: 'b',
  num: 1
}]
let arrayThid = [{
  name: 'a',
  num: 1
}, {
  name: 'c',
  num: 1
}]
</script>