JavaScript how to sort date by most recent first-CodePudding

I am trying to sort JSON objects received from an API so that the most recent datetime is shown first. But the way I am currently doing it is sorting Dec 2022 as more recent than Jan 2023.

Here is what I'm working with currently:

result = [
{
   "date": "21/12/2022",
    "time": "10:41:10",
},
{
    "date": "20/12/2022",
    "time": "12:42:21",
},
{
    "date": "15/12/2022",
    "time": "09:26:02",
},
{
    "date": "14/12/2022",
    "time": "10:20:54",
},
{
    "date": "09/01/2023",
    "time": "18:58:17",
},
{
    "date": "09/01/2023",
    "time": "18:57:34",
},  
{
    "date": "08/01/2023",
    "time": "12:12:38",
}]

if (result.length > 1) {
        result.sort((a, b) => {
            const dateTime1 = new Date(a.date   a.time);
            const dateTime2 = new Date(b.date   b.time);

            return dateTime2 - dateTime1;
        });

        console.log(result);
};

Which gives me:

{date: "21/12/2022", time: "10:41:10...}
{date: "20/12/2022", time: "12:42:21...}
{date: "15/12/2022", time: "09:26:02...}
{date: "14/12/2022", time: "10:20:54...}
{date: "09/01/2023", time: "18:58:17...}
{date: "09/01/2023", time: "18:57:34...}
{date: "08/01/2023", time: "12:12:38...}

How can I sort this in a way that it doesn't think 2022 is more recent than 2023?

CodePudding user response：

Issue with your code is date creation.

You can use following snippet to create date as date constructor does not accept DD/MM/YYYY.

const createDate = (d, t) => {
  const [date, month, year] = d.split('/')
  const [hours, mins, secs] = t.split(':')
  return new Date(year, month - 1, date, hours, mins, secs)
}

Also, a.date a.time is incorrect. You are concatinating both but without space. So following will be the output:

Date: "21/12/2022"
Time: "10:41:10"
Output: "21/12/202210:41:10"

Following is a working example

result = [{
    "date": "21/12/2022",
    "time": "10:41:10",
  },
  {
    "date": "20/12/2022",
    "time": "12:42:21",
  },
  {
    "date": "15/12/2022",
    "time": "09:26:02",
  },
  {
    "date": "14/12/2022",
    "time": "10:20:54",
  },
  {
    "date": "09/01/2023",
    "time": "18:58:17",
  },
  {
    "date": "09/01/2023",
    "time": "18:57:34",
  },
  {
    "date": "08/01/2023",
    "time": "12:12:38",
  }
]

const createDate = (d, t) => {
  const [date, month, year] = d.split('/')
  const [hours, mins, secs] = t.split(':')
  return new Date(year, month - 1, date, hours, mins, secs)
}

if (result.length > 1) {
  result.sort((a, b) => {
    const dateTime1 = createDate(a.date, a.time);
    const dateTime2 = createDate(b.date, b.time);
    return dateTime2 - dateTime1;
  });

  console.log(result);
};

As correctly mentioned by @RobG

That should be new Date(year, month - 1, date, hours, mins, secs), but for sorting it won't matter if all months are 1.

CodePudding user response：

You can convert your date and time in YYYY-MM-DD HH:MM:SS format and then lexicographically sort it.

const arr = [ { "date": "21/12/2022", "time": "10:41:10", }, { "date": "20/12/2022", "time": "12:42:21", }, { "date": "15/12/2022", "time": "09:26:02", }, { "date": "14/12/2022", "time": "10:20:54", }, { "date": "09/01/2023", "time": "18:58:17", }, { "date": "09/01/2023","time": "18:57:34", }, { "date": "08/01/2023", "time": "12:12:38", }],
    sorted = arr.map(o => [o, o.date.split('/').reverse().join('-')   '_'   o.time])
               .sort((a, b) => b[1].localeCompare(a[1]))
               .map(([o]) => o);
console.log(sorted);

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