将对象数组分组并添加时间属性

Question

我有一组自定义对象，其中填充了用户输入。该数组如下所示：

let array = [
  {Course: "Design", Hours: "01:00:00", Week: "1"}, 
  {Course: "Design", Hours: "01:00:00", Week: "3"}, 
  {Course: "Design", Hours: "01:00:00", Week: "2"}, 
  {Course: "Design", Hours: "01:00:00", Week: "1"}, 
  {Course: "Design", Hours: "01:00:00", Week: "2"}
]

我需要修改此数组，以便计算同一周的所有小时数，并根据周的顺序将值放入数组中。我想要的结果是这样的：

let newArray = [
  {Course: "Design", Hours: "02:00:00", Week: "1"}, 
  {Course: "Design", Hours: "02:00:00", Week: "2"},
  {Course: "Design", Hours: "01:00:00", Week: "3"},  
]

所以基本上我需要同时排序和计算总和。

Answer 1

您可以使用moment.js来获取时间字符串的总和。

要按周对项目进行分组，您可以使用 .reduce。

最后，要按 Week 对项目进行排序，请使用 .sort:

let array = [
  {Course: "Design", Hours: "01:00:00", Week: "1"}, 
  {Course: "Design", Hours: "01:00:00", Week: "3"}, 
  {Course: "Design", Hours: "01:00:00", Week: "2"}, 
  {Course: "Design", Hours: "01:00:00", Week: "1"}, 
  {Course: "Design", Hours: "01:00:00", Week: "2"}
];

const addTwoTimeStrs = (a, b) => {
  let sum = moment.duration(a).add(moment.duration(b));
  sum = moment.utc(sum.asMilliseconds()).format("HH:mm:ss");
  return sum;
}

const arr = Object.values(
  array.reduce((acc,item) => {
    const { Hours: hours, Week: week } = item;
    const weekItem = acc[week];
    acc[week] = weekItem
      ? { ...weekItem, Hours: addTwoTimeStrs(weekItem.Hours,hours) }
      : item;
    return acc;
  }, {})
);

const res = arr.sort((a,b) => Number(a.Week) - Number(b.Week));

console.log(res.map(e => e.Hours));

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将对象数组分组并添加时间属性

Group an array of objects and add the time attribute

javascript

arrays

sorting

reduce

datetime