Comments on: How to format numbers in JavaScript flexibly and efficiently

By: shelly

shelly — Thu, 22 May 2008 12:07:49 +0000

Hi,
i need a script which can fix the length of a number with given number of digits (not adding decimal point). e.g. need to have a 2 digit number so method(5) should return 05.
i need this for month and days of a date. How to do this?

By: Matias Moncho

Matias Moncho — Tue, 08 Apr 2008 19:57:55 +0000

@Angel: Yes, somehow my clippboard didn’t paste the whole code.
Here I let you a link to a file white the “round” method:
http://www.clanpesto.com.ar/round.js

Regards!

By: Angel

Angel — Tue, 08 Apr 2008 18:57:57 +0000

Matias, something is missing in your code, before the brace ( { ) at the end of
var strToRound = (toRound.toString().indexOf(”.”) = 5)

By: Matias Moncho

Matias Moncho — Mon, 07 Apr 2008 21:51:38 +0000

Hi, I found another bug on round function, even with Ron’s patch.
As Ron said, if you enter: “11.95″ with format “#.0″ you get “12.0″, that’s ok.
But on negative numbers, ie: “-11.95″ with format “#.0″ you get “-10.0″. That’s wrong, because the nearest number to -11.95 is -12.

So, here is my patch for this function. I recoded it from scratch, And tested a bit.
[code]
Number.prototype.round = function(decimals) {
if (decimals > 0) {
var toRound = this * (Math.pow(10, decimals));
var strToRound = (toRound.toString().indexOf(”.”) = 5) {
return ((parseInt(strToRound.substring(0, strToRound.indexOf(”.”)), 10) (this > 0 ? 1 : (-1))) / (Math.pow(10, decimals)));
} else {
return (parseInt(strToRound.substring(0, strToRound.indexOf(”.”)), 10) / (Math.pow(10, decimals)));
}
}
return this;
}
[/code]

I hope that helps someone!.

By: Angel

Angel — Wed, 02 Apr 2008 23:45:03 +0000

Thanks for this excellent script, Xaprb. It’s solved my problem in one go.
I am having a problem, though; I want fixed-width numbers so they are aligned in columns in a textarea, so I’m using “?????.####” as the format. However, if the numbers are negative, I get one more column since the minus sign is inserted after the spaces and before the number.
I need the minus sign to take the space of one of the “?”, so the columns are aligned correctly irrespective of the sign.

By: Bruce

Bruce — Wed, 06 Feb 2008 00:35:56 +0000

Hey Xaprb, I tried the following in my code:

new Number(85.68).numberFormat(’$#,###.##’);

but it returned $86.00. I then tried the same number and format on your demo page, and it correctly displayed $85.68.

Is there a difference between the demo page code and what’s in the download? My version of number-functions.js is dated 6/15/2007.

By: Livia

Livia — Wed, 09 Jan 2008 09:15:56 +0000

Thanks very much! That was great, exacly what I needed

By: Jon

Jon — Thu, 03 Jan 2008 17:33:11 +0000

Great script!

By: Xaprb

Xaprb — Wed, 20 Jun 2007 02:05:57 +0000

A new version is released with a fix for the zero-padding of negative numbers.

If you find bugs, please send me test cases I can use to reproduce and add to the unit test suite. One test per line, like “input”, “format”, “expected” is best. For example,

-1, “#,#.00″, “-1.00″

Is a great test case. I can plug that directly into the unit tests, run it, and if it gives back “-01.00″ it will fail the test. This makes it much easier and more convenient for me to fix bugs.

Sponsoring bug fixes won’t hurt either ;-)

By: Andrew Janssen

Andrew Janssen — Sat, 02 Jun 2007 00:21:16 +0000

Thanks Xaprb. You rock.