Sorting an array twice

Question

I have the following array:

var array = [{
    "name": "Item 1",
    "LineNumber": "10",
    "size": "5"
    },
    {
    "name": "Item 2",
    "LineNumber": "30",
    "size": "5"
    },
    {
    "name": "Item 3",
    "LineNumber": "30",
    "size": "4"
    },
    {
    "name": "Item 4",
    "LineNumber": "20",
    "size": "5"
    }]

Using the following, I am able to sort by line number:

      array.sort(function(a, b) {
        return a.LineNumber - b.LineNumber;
      });

In some situations with large data, I run into an issue where items will share the same line number, but their size will be different (ie. Item 2 and Item 3). I would like to first sort by the line number, and then order by size based on how the first sort is returned. Is it possible to achieve this in one sort compare function?

Do the first comparison, if they are equal fallback to a second comparison test and return that. — MinusFour, Oct 16 '15 at 15:29

score 7 · Answer 1 · edited Oct 16 '15 at 15:33

7

Try this:

array.sort(function(a, b) {
  if (a.LineNumber == b.LineNumber)
    return a.size - b.size;
  return a.LineNumber - b.LineNumber;
});

edited Oct 16 '15 at 15:33

Sarjan Desai

3,683
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answered Oct 16 '15 at 15:29

0FiRE0

146
5

score 0 · Answer 2 · answered Oct 16 '15 at 15:29

0

You just need to add more logic to your sort function.

  array.sort(function(a, b) {
    if (a.LineNumber === b.LineNumber) {
         return a.size - b.size;
    }
    return a.LineNumber - b.LineNumber;
  });

answered Oct 16 '15 at 15:29

Schleis

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7
68
87

Sorting an array twice

2 Answers2