Sort an array with objects date property

Question

I have an array with objects that looks like this:

{
 Title: "Title",
 Url: "myUrl",
 publishedDate: "19/01/2021"
  },
  {
   Title: "Title 2",
Url: "myUrl",
publishedDate: "17/12/2020"
  },
  {
  Title: "Title 3",
Url: "myUrl",
publishedDate: "11/03/2021"
  },
  {
Title: "Title 4",
Url: "myUrl",
publishedDate: "11/12/2020"
  }

I have saved them in my state (array).

this.state.data

I want to order the objects based on the property "publishedDate" (and without using the new Date() due to memory efficiency). I try:

console.log(this.state.data.sort(function(a, b) {
  var c = new Date(a.publishedDate);
  var d = new Date(b.publishedDate);
  return c.getTime() - d.getTime();
}))

But the objects are not in order. What is wrong in the code? Playground:

https://www.typescriptlang.org/play?#code/FAYw9gdgzgLgBAQwE5IQTzgXjgb2HOAEwRgQC44BtPOAFQEsYAbAUwoCIHmX2AafAKpImHALZohTPvgAOAVwBGTelAAWLQgBESbOOwCMATgD0ABn3GATKcv72+OAF9+BGgS6sOHlnEvTJYhLC0vJKKupaOhz6AOzG+pZWNqb2BM4Obt5ejKxwAMz+woGSIYrKahraMLoGFqZ5SbapTi64wFl63nAALIUieuIl-KHlEVU1+hYJjSkOjg4AusDzwKCQUGCsAHRMYADmABTIqGhbxKRbG0gwBwBmchAgMPSQR7xwCgCUbQQAbshwEBYOAQFgAdzg4yOWxG4UqOk+AG4HP8kERgaCIVCFDCynDItUkQ4kCwYHIkBBAVs9qSGKIWAdvgBaIjU2n0emM5GOT6fYBAA

"and without using the new Date() due to memory efficiency" - Why should new Date() be a problem? — Andreas
– Andreas, Commented Dec 18, 2020 at 12:13
Because allocating memory inside of a sort function. Have been discussed here: stackoverflow.com/questions/10123953/… — SharePointBeginner
– SharePointBeginner, Commented Dec 18, 2020 at 12:14
What have you tried to solve this on your own? Splitting the date into its parts and comparing them shouldn't be that difficult — Andreas
– Andreas, Commented Dec 18, 2020 at 12:15
Yeah you could do this, just write your own compareDates function and your good to go. Split the date in his 3 components using "/" as delimiter — Syder
– Syder, Commented Dec 18, 2020 at 12:17
There's exactly one comment, without any further facts to prove its assumption. Without an exhaustive analysis with a profiler you really shouldn't think about "memory efficiency". — Andreas
– Andreas, Commented Dec 18, 2020 at 12:18

Nikhil Patil · Accepted Answer · 2020-12-18 12:34:40Z

3

If the date format is always the same, you can just create the string in format YYYYMMDD and then compare -

var data = [{
  Title: "Title",
  Url: "myUrl",
  publishedDate: "19/01/2021"
}, {
  Title: "Title 2",
  Url: "myUrl",
  publishedDate: "17/12/2020"
}, {
  Title: "Title 3",
  Url: "myUrl",
  publishedDate: "11/03/2021"
}, {
  Title: "Title 4",
  Url: "myUrl",
  publishedDate: "11/12/2020"
}]

var sortedData = data.sort(function(a, b) {
  a = a.publishedDate.split('/').reverse().join('');
  b = b.publishedDate.split('/').reverse().join('');
  return a > b ? 1 : a < b ? -1 : 0;
});

console.log(sortedData);

The solution here also suggests the same (as well as to use .localeCompare as an alternative)

answered Dec 18, 2020 at 12:34

Nikhil Patil

2,5331 gold badge9 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Terry Lennox · Accepted Answer · 2020-12-18 12:20:33Z

1

You can use the Date.UTC method that accepts year, month index, day to create your dates and pass these values by parsing your input dates strings like so:

this.state =  { data: [{ Title: "Title", Url: "myUrl", publishedDate: "19/01/2021" }, { Title: "Title 2", Url: "myUrl", publishedDate: "17/12/2020" }, { Title: "Title 3", Url: "myUrl", publishedDate: "11/03/2021" }, { Title: "Title 4", Url: "myUrl", publishedDate: "11/12/2020" }]}; 

console.log(this.state.data.sort(function(a, b) {
  var c = Date.UTC(a.publishedDate.split("/")[2], a.publishedDate.split("/")[1] - 1, a.publishedDate.split("/")[0]);
  var d = Date.UTC(b.publishedDate.split("/")[2], b.publishedDate.split("/")[1] - 1, b.publishedDate.split("/")[0]);
  return c - d;
}))

edited Dec 18, 2020 at 12:20

answered Dec 18, 2020 at 12:17

Terry Lennox

30.9k5 gold badges36 silver badges45 bronze badges

3 Comments

Andreas Over a year ago

Date.UTC() doesn't change that much in regards to "memory efficiency", but that "restriction" doesn't make sense at all in the first place...

Terry Lennox Over a year ago

It's just one other way of doing it I guess, if the OP wishes to avoid new Date(), that's ok by me :-)

SharePointBeginner Over a year ago

@Andreas "But that "restriction" doesn't make sense at all in the first place." I guess you have a good knowledge about my application. :) Dont understand why you are "policing" around like this, that makes no sense to me and its not the first time I see you like this.

Collectives™ on Stack Overflow

Sort an array with objects date property

2 Answers 2

Comments

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related