Sorting decimal numbers using Intl.Collator and the option to enable numeric pares decimals incorrectly.

On some browsers paring "0.005" and "0.05" returns "0" as in the numbers are the same.

Results in different browsers:

• Chrome 54 = 0
• Firefox 49 = 0
• Edge = -1
• IE 11 = -1

// Returns 0
console.log(new Intl.Collator(undefined, { numeric: true})pare(0.000005, 0.05))

Sorting decimal numbers using Intl.Collator and the option to enable numeric pares decimals incorrectly.

On some browsers paring "0.005" and "0.05" returns "0" as in the numbers are the same.

Results in different browsers:

• Chrome 54 = 0
• Firefox 49 = 0
• Edge = -1
• IE 11 = -1

// Returns 0
console.log(new Intl.Collator(undefined, { numeric: true}).pare(0.000005, 0.05))

Anyone that can tell me whats wrong?

Reported as bug in Firefox: https://bugzilla.mozilla/show_bug.cgi?id=1312388

• javascript
• ecmascript-intl

Share Improve this question Follow edited Oct 26, 2016 at 20:23 Jeff Walden 7,11822 gold badges4040 silver badges5555 bronze badges asked Oct 18, 2016 at 11:54 NisdNisd 1,1531111 silver badges2222 bronze badges 2

• 1 i get -1 on edge. – Nina Scholz Commented Oct 18, 2016 at 12:02
• Thanks @NinaScholz, I have updated the question with the different results I get. – Nisd Commented Oct 18, 2016 at 13:25

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2 Answers 2

Sorted by: Reset to default 5

As André Bargull observes in the Firefox bug report, numeric sorting considers only decimal digit sequences, i.e. in the Unicode category of Number, by their numeric values. That is, when paring two otherwise-identical strings containing decimal numbers with fractional ponents, the entire decimal numbers aren't considered for their numeric value -- because U+002E FULL STOP isn't in the Number category (it's instead in the Punctuation category).

So then, when we pare these two strings -- "0.05" and "0.000005" -- we effectively are paring these arrays of elements:

["0", ".", "05"]
["0", ".", "000005"]

and then when digit sequences are considered by their numeric values, we're paring

[0, ".", 5]
[0, ".", 5]

which are equal, and so pare should return 0 when paring them. Firefox and Chrome are right here, and IE and Edge are mistaken.

Workaround

Multiply values by 100_000_000 to get rid of decimals

const a = 0.000005;
const b = 0.05;

// NOTE: assume this value is ok for now but prefer
// to get the length of the smallest value and use
// this value in the powers of 10
// for example, [0,09, 0,003] => Math.pow(10, 3)
// But in this case we can go beyond the Number.MAX_SAFE_INTEGER
const NORMALIZE_VALUE = 100_000_000;

const normalizedA = a * NORMALIZE_VALUE;
const normalizedB = b * NORMALIZE_VALUE;

console.log(new Intl.Collator(undefined, { numeric: true}).pare(normalizedA, normalizedB));