Javascript 计算所提供年份和月份的对象数组中的数组数

假设我有一个对象数组，如下所示：

const timeValue = ["October 2020"]
const information = [
    {name: 'alpha',details: [
        {"attachment": [123, 456], "receivedOn":"2020-10-24 04:05:16.000Z"},
        {"attachment": [1454, 1992], "receivedOn":"2020-10-24 04:05:16.000Z"}]}, 
    {name: 'beta',details: [
        {"attachment": ["12", 189] ,  "receivedOn":"2020-10-24 04:05:16.000Z"},
        {"attachment": ["maggi", 1890, 2000],  "receivedOn":"2021-02-24 04:05:16.000Z"},
        {"attachment": [1990, 2001, 2901], "receivedOn":"2020-12-24 04:05:16.000Z"}]},
    {name: 'theta',details: [
        {"attachment": [1902, 1189] ,  "receivedOn":"2021-10-24 04:05:16.000Z"}] }];

我想获得给定时间值的alpha和beta计数，即预期O/p：

{“alpha”：4，“beta”：2}

const result = information.reduce((acc, curr) => {
   if (acc[curr.name] === undefined) acc[curr.name] = 0;
       curr.details.forEach((d) => (acc[curr.name] += d.attachment.length));
       return acc;
}, {});

为此，我尝试了，我能够得到每个名字的总附件数。即

{alpha:4，beta:8，theta:2}

const result = information.reduce((acc, curr) => {
   if (acc[curr.name] === undefined) acc[curr.name] = 0;
       curr.details.forEach((d) => (acc[curr.name] += d.attachment.length));
       return acc;
}, {});

console.log（result）

将输出作为

{alpha:4，beta:8，theta:2}

const result = information.reduce((acc, curr) => {
   if (acc[curr.name] === undefined) acc[curr.name] = 0;
       curr.details.forEach((d) => (acc[curr.name] += d.attachment.length));
       return acc;
}, {});

---

但我想知道2020年10月仅有的附件数量。有可能实现吗？如果有任何其他信息，请告诉我。

，使用>，只需在您的forEach中添加条件，如果您只对年-月比较感兴趣，您可以这样做：

var result = information.reduce((acc, curr) => {
   if (acc[curr.name] === undefined) acc[curr.name] = 0;
       curr.details.forEach((d) => {
            var receivedOn = new Date(d.receivedOn);
            acc[curr.name] += (receivedOn.getFullYear() == 2020 && receivedOn.getMonth() == 9 ? d.attachment.length : 0)});
       return acc;
}, {});

---

timeValue

的可能值是什么？该数组中可以有多个值吗？不，timeValue中只能有一个元素。您的问题与此非常相似：即使是数组内容也是如此。你知道吗？谢谢，这正是我需要的