Formatting numbers using DecimalFormat

java decimalformat

86,283

Solution 1

This doesn't seem to be solved by a single formatter. I suggest you use "0.00" format and replace ".00" with an empty string.

public static String myFormat(double number) {
  DecimalFormat df = new DecimalFormat("0.00");
  return df.format(number).replaceAll("\\.00$", "");
}

Solution 2

There is a slight difference between these two formats. The "#.##" means it will print the number with maximum two decimal places whereas "#.00" means it will always display two decimal places and if the decimal places are less than two, it will replace them with zeros. see the example below with output.

public static final DecimalFormat df1 = new DecimalFormat( "#.##" );
public static final DecimalFormat df2 = new DecimalFormat( "#.00" );

System.out.println(df1.format(7.80));
System.out.println(df1.format(85));
System.out.println(df1.format(85.786));

System.out.println(df2.format(7.80));
System.out.println(df2.format(85));
System.out.println(df2.format(85.786));

And the output will be

Solution 3

I don't think it's possible, at least not with Java SE formatters. You need to make a custom formatter. I would do it like this

String res = df.format(number).replace(".00", "");

Solution 4

Use the BigDecimal number class instead:

e.g. if n is a BigDecimal, then you can use

String s = NumberFormat.getCurrencyInstance().format(n);

By the way, it's best practice to use BigDecimal when working with money.

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86,283

Author by

Jon

Updated on July 30, 2022

Comments

Jon almost 2 years
I am trying to format prices using DecimalFormat, but this isn't working for all variations.
```
DecimalFormat df = new DecimalFormat("0.##")
df.format(7.8)
df.format(85.0)
```
prints
```
7.80
```
and
```
85
```
but "7.79999" gets formatted as "7.8", not "7.80". I have tried doing things this way
```
DecimalFormat df = new DecimalFormat("0.00")
```
to force two dp, but then "85.0" gets formatted as "85.00" not "85"!

Is there a way of capturing all variations, so that prices are printed either as #, ##, or #.##? For example:

5, 55, 5.55, 5.50, 500, 500.40
Jon about 11 years

Thanks, but this doesn't remove the trailing zero's, e.g. 5.0 and 5.00
Jon about 11 years

Yes I know thanks, but I need something that covers both these functions, so that 7.79999 prints 7.80 and 85.00 prints 85
Bathsheba about 11 years

Ok, compare the string to this regex [0-9]*[.]0+: if (s.matches("[0-9]*[.]0+")) then "strip off the stuff on and after the period". This will also take care of things like 5. and even 3 digit currencies (there are some of these around still).
Raza about 11 years

I am afraid it is not possible with the built in formatters. You will have to format the resulting String manually. Perhaps by removing the last characters if they are 00s
Raza about 11 years

Ooops, did not see the answer from @EvgeniyDorofeev, that's the only possibility for you
izogfif over 5 years

What if decimal separator is comma (it's taken from default locale, no)? Will it still work?
Tyler2P over 3 years

Please don't post only code as answer, but also provide an explanation what your code does and how it solves the problem of the question. Answers with an explanation are usually more helpful and of better quality, and are more likely to attract upvotes.