Java formatting, negative values, zero padding

Question

Here's a quote from: http://docs.oracle.com/javase/1.5.0/docs/api/java/util/Formatter.html

'd' '\u0054' Formats the argument as a decimal integer. The localization algorithm is applied.

If the '0' flag is given and the value is negative, then the zero padding will occur after the sign.

I feel frustrated, trying to learn this formatting thing but that tutorial is just so cluttered and messy.

String.format("%03d", int);

I am trying to understand where exactly this whole \u0054 should go but I have just no idea, I must be missing something very obvious or something...

Edit:

What I want to achieve: Positive 10: 010 Negative 10: -10 Negative result I want to achieve: -010

'\u0054' is equivalent to 'd'

nhahtdh
– nhahtdh

2012-09-03 18:55:02 +00:00
Commented Sep 3, 2012 at 18:55 — nhahtdh
– nhahtdh, Commented Sep 3, 2012 at 18:55

Peter Lawrey · Accepted Answer · 2012-09-03 19:16:50Z

9

\u0054 is d

You can do

((i < 0) ? "-" : "") + String.format("%03d", Math.abs(i));

edited Sep 3, 2012 at 19:16

answered Sep 3, 2012 at 18:54

Peter Lawrey

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2 Comments

Deragon Over a year ago

If I just keep it the way I have now, the negative (-) replaces a zero so: positive 10: 010 for example, but the negative would be -10 but I want it to say -010

obataku Over a year ago

@Deragon something close which maintains consistency should be "%+04d" which will produce "+010" and "-010".

Chochos · Accepted Answer · 2012-09-03 19:12:23Z

7

Try String.format("% 4d", i) then (with a space between % and 4); it's using 4 positions, zero-padded and it leaves an extra space for positive values, so you get " 010" and "-010". You can trim() the string afterwards to get rid of the initial space (or do something like if (i>0) s=s.substring(1) or something).

answered Sep 3, 2012 at 19:12

Chochos

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2 Comments

BamaPookie Over a year ago

I like this answer. It gives proper padding for non-negative values. You need a "% 04d" to maintain the proper number of leading zeros, though.

jannis Over a year ago

Shouldn't it be String.format("% 04d", i)?

lkreinitz · Accepted Answer · 2021-08-10 03:01:16Z

0

The following works

public class MyProgram
{
    public static void main(String[] args)
    {
        int n = -13754;
        int p = 2234;
        String buffer = String.format("%08d", n);
        System.out.println(buffer);
        buffer = String.format("%08d", p);
        System.out.println(buffer);
    }
}

output

-0013754
00002234

For your example "%03d" is what you would use.

answered Aug 10, 2021 at 3:01

lkreinitz

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