How to avoid negative 0 or -0 values in javascript

Question

I have tried using toString() and the bitwise operator | but I would like to use the precision and string output. As @trincot mentioned, it is caused by the precision value for e.g. -0.45 will result in -0. I have the code here.

typeof predictedHours //number e.g. -0.45
precision = 0
value={predictedHours.toFixed(precision)}
typeof value //string e.g. "-0"

Question - Is there a one liner to convert -0 to 0 in this line - value={predictedHours.toFixed(precision)}?

Lots of relevant comments in this question: https://stackoverflow.com/questions/7223359/are-0-and-0-the-same — Jonas Høgh, Oct 24 '19 at 19:14
Possibly question is triggered by `-0.001.toFixed(2) === "-0"`? — trincot, Oct 24 '19 at 19:15
@trincot You got it correct. it is triggerred exactly because of that and I have a JSX element to throw the value in. — technazi, Oct 24 '19 at 19:16
So what you want the string to be in that case? Just "0" instead of "-0"? — trincot, Oct 24 '19 at 19:16
Downvoters, I am sorry for bad language. Maybe I deserve the downvotes. — technazi, Oct 24 '19 at 19:19

Ry- · Accepted Answer · 2023-01-30T19:31:42.580

12

I’m not aware of a particularly clean way to do it, but there’s always:

value={predictedHours.toFixed(0).replace('-0', '0')}

Or, in general:

value={predictedHours.toFixed(precision).replace(/^-([.0]*)$/, '$1')}

edited Jan 30 '23 at 19:31

answered Oct 24 '19 at 19:20

Ry-

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You got it Sir. Thank you. – technazi Oct 24 '19 at 19:21

score 2 · Answer 2 · answered Jan 19 '22 at 22:13

2

use Math.abs() to replace a -0 with an absolute number i.e. 0.

answered Jan 19 '22 at 22:13

Jeremy

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technazi · Answer 3 · 2019-10-25T15:37:40.740

0

I think @trincot's suggestion is better so as to avoid any decimals like -0.48.toFixed(2) to be converted to positive. Took me a while to understand the regex. Just a little caveat though: Due to operator precedence negative numbers stay negative with toFixed when enclosed in brackets. Some examples here:

-0.001.toFixed(2).replace(/^-0$/, "0")
//0 '0'

console.log((-0.48).toFixed(0).replace(/^-0$/, '0')); Correct
//-0 '0'

console.log((-0.48).toFixed(2).replace(/^-0$/, '0')); Correct
//-0.48 '-0.48'

console.log(-0.48.toFixed(0).replace(/^-0$/, '0'));
//0 '0'

console.log(-0.48.toFixed(2).replace(/^-0$/, '0'));
//-0.48 '-0.48'

Also have a look at the examples here - toFixed()

edited Oct 25 '19 at 15:37

answered Oct 24 '19 at 20:52

technazi

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Not sure what you mean by real decimals, but try with `(-0.0048).toFixed(2)`. – Ry- Oct 25 '19 at 05:23
Yeah good point. Is there a way to avoid that by adding any optional characters in regex? – technazi Oct 25 '19 at 15:38
`console.log((-0.0048).toFixed(2).replace(/^-0.?0?/, '0'));` would return 00 – technazi Oct 25 '19 at 15:50
I mean… I’d use `.replace('-0', '0')`, as seen. `toFixed` isn’t localized and doesn’t produce scientific notation, so it’s quite safe. – Ry- Oct 25 '19 at 17:06

Saurye · Answer 4 · 2020-11-15T12:07:30.357

0

You can also do value = +predictedHours.toFixed(precision) || 0 because -0 || 0 is 0

edited Nov 15 '20 at 12:07

answered Feb 09 '20 at 07:48

Saurye

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`-0 || 0` won't work here, because of `toFixed` returning a string and `"-0" !== 0`. – parentNode Nov 13 '20 at 14:02
You're right, fixed my answer. Added a `+` to turn it into a number :) – Saurye Nov 15 '20 at 12:07

How to avoid negative 0 or -0 values in javascript

4 Answers4