Sort Arr Numbers MM/DD/YYYY When they're strings?

Question

How do I sort these descending correctly? I've tried arr.sort() arr.sort().reverse() , looked all over stack overflow ... and I cannot find a way to do this. Everything tries to sort them but does it wrong.

[
  '1/19/2024',  '1/20/2023',
  '10/21/2022', '11/18/2022',
  '12/16/2022', '3/17/2023',
  '6/10/2022',  '6/16/2023',
  '6/17/2022',  '6/21/2024',
  '6/24/2022',  '6/3/2022',
  '6/31/2022',  '7/15/2022',
  '7/8/2022',   '8/19/2022',
  '9/15/2023',  '9/16/2022'
]

Then I need to take those and turn them into the actual month. Jan, Feb, etc. instead of the numerical value ...

How about casting each string into a `new Date`. A comparison based on each date's time (in msec / see ... `getTime`) then should be an easy task ... `arr.sort((a, b) => new Date(b).getTime() - new Date(a).getTime());` — Peter Seliger, May 30 '22 at 16:03
@Enve the result from that is a string that isn't sorted properly ... 6/10/2022 7/15/2022 12/16/2022 9/16/2022 6/17/2022 11/18/2022 8/19/2022 10/21/2022 6/24/2022 6/31/2022 6/3/2022 7/8/2022 9/15/2023 6/16/2023 3/17/2023 1/20/2023 1/19/2024 6/21/2024 — hattoncm, May 30 '22 at 16:13
I answered this 7 years ago: [Sort a string date array](https://stackoverflow.com/questions/30691066/sort-a-string-date-array/30691186#30691186) — Yogi, May 30 '22 at 16:16

score 0 · Answer 1 · answered May 30 '22 at 16:10

So, easiest way is to convert strings to dates, sort it and then convert dates to string format back, see:

const origArr = [
  '1/19/2024', '1/20/2023',
  '10/21/2022', '11/18/2022',
  '12/16/2022', '3/17/2023',
  '6/10/2022', '6/16/2023',
  '6/17/2022', '6/21/2024',
  '6/24/2022', '6/3/2022',
  '6/31/2022', '7/15/2022',
  '7/8/2022', '8/19/2022',
  '9/15/2023', '9/16/2022'
];

// create array of dates
const datesArr = origArr.map(str => new Date(str));

// sort array of dates
const datesSortedArr = datesArr.sort((a,b) => b - a);

// convert dates to strings
const sortedArr = datesSortedArr.map(item => {
  const month = item.getMonth() + 1;
  const day = item.getDate();
  const year = item.getFullYear();
  
  return `${month}/${day}/${year}`;
});
console.log('sortedArr:', sortedArr);

This worked beautifully. Makes sense to convert to strings and then sort because .sort() runs off of strings. Thank you for your help. — hattoncm, May 30 '22 at 16:16

score 0 · Answer 2 · answered May 30 '22 at 16:18

you can convert them to Date order them and than convert them back to the original format

const dates = [
  '1/19/2024',  '1/20/2023',
  '10/21/2022', '11/18/2022',
  '12/16/2022', '3/17/2023',
  '6/10/2022',  '6/16/2023',
  '6/17/2022',  '6/21/2024',
  '6/24/2022',  '6/3/2022',
  '6/31/2022',  '7/15/2022',
  '7/8/2022',   '8/19/2022',
  '9/15/2023',  '9/16/2022'
]

const toDate = string => {
 const [month, day, year] = string.split('/')
 
 return new Date([year, month.padStart(2, '0'), day.padStart(2, '0')].join('-'))
}


const toString = date => [date.getMonth() + 1, date.getDate(), date.getFullYear()].join('/')

const reorder = data => {
 const dates = data.map(toDate)
 dates.sort((a, b) => b - a)
 
 return dates.map(toString)
}

console.log(reorder(dates))

Sort Arr Numbers MM/DD/YYYY When they're strings?

2 Answers2