javascript sort array double sort

Question

I have an array MyArrayOfItems of Item objects with objects that look like this:

Item
{
  ContainerID: i, // int
  ContainerName: 'SomeName', // string
  ItemID: j, // int
  ItemName: 'SomeOtherName' // string
}

I want to sort this array so that it's sorted by ContainerID and then by ItemName alphabetically.

I have a custom sort function that so far looks like this:

function CustomSort(a, b) {

  Item1 = a['ContainerID'];
  Item2 = b['ContainerID'];

  return Item1 - Item2;
}

MyArrayOfItems.sort(CustomSort);

This sorts by ContainerID but how do I then sort by ItemName?

Thanks.

possible duplicate of [Javascript sort array by two fields](http://stackoverflow.com/questions/6129952/javascript-sort-array-by-two-fields) — Felix Kling, May 01 '12 at 20:23
So? You can easily compare stings with `<` and `>` though I agree that `localCompare` is a better way. I thought the overall question was about how to sort by two properties, in which case it is clearly a duplicate. — Felix Kling, May 01 '12 at 21:28

Shiplu Mokaddim · Accepted Answer · 2012-05-01T21:32:51.307

6

Use String.localeCompare function. And use it when ContainerID of a and b are equal.

function CustomSort(a, b) {
  var Item1 = a['ContainerID'];
  var Item2 = b['ContainerID'];
  if(Item1 != Item2){
      return (Item1 - Item2);
  }
  else{
      return (a.ItemName.localeCompare(b.ItemName));
  }
}

To tweak the sorting order you can always put - in front of any return expression.

edited May 01 '12 at 21:32

answered May 01 '12 at 20:25

Shiplu Mokaddim

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It should. As its in JavaScript 1.2 which is very old. – Shiplu Mokaddim May 01 '12 at 20:35
localcompare is a good choice, but as I remember chrome had issues with it..http://code.google.com/p/v8/issues/detail?id=459 – Rajat Singhal May 01 '12 at 20:38
2

`Item1 - Item2 !=0` can be simplified to `Item1 != Item2`. – Felix Kling May 01 '12 at 21:30
ok, thanks Felix; I put Item1 !== Item2 to use the triple comparator. – frenchie May 01 '12 at 21:33

Rajat Singhal · Answer 2 · 2012-05-01T20:33:36.523

5

function CustomSort(a, b) {

  Item1 = a['ContainerID'];
  Item2 = b['ContainerID'];
  if(Item1 - Item2 !=0){
      return Item1 - Item2;
  }
  else{
      if (a.ItemName < b.ItemName)
         return -1;
      if (a.ItemName > b.ItemName)
         return 1;
      return 0;
  }
}

edited May 01 '12 at 20:33

answered May 01 '12 at 20:28

Rajat Singhal

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ok, thanks; upvoted because it also works. I prefer localeCompare though. – frenchie May 01 '12 at 20:37

score 0 · Answer 3 · answered Mar 17 '22 at 00:08

0

A nice simplification of this is:

function CustomSort(a, b) {
  var Item1 = a['ContainerID'];
  var Item2 = b['ContainerID'];
  

 if(Item1 != Item2){
      return (Item1 - Item2);
  }
  else{
      return (a.ItemName.localeCompare(b.ItemName));
  }
}

answered Mar 17 '22 at 00:08

Jonathan Tuzman

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javascript sort array double sort

3 Answers3

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