How to remove trailing zeros from a double

Question

For example I need 5.0 to become 5, or 4.3000 to become 4.3.

Note: Unlike the top answer in the linked question, all of these answers rely on an expected input of only one decimal place. Everything longer than one decimal place will be rounded, which may not be desired behaviour. — tommoyang, Jun 04 '14 at 02:07
This is ugly as hell but it works: String.format(doubleVal).replaceAll("\\.0+$", ""); — mvmn, Jan 18 '19 at 15:55
P.S. Ended up using this: DecimalFormat("#.################").format(doubleVal); // This ensures no trailing zeroes and no separator if fraction part is 0 (there's a special method setDecimalSeparatorAlwaysShown(false) for that, but it seems to be already disabled by default). But will produce up to 16 digits of fractional part (and you can put more # there if you think 16 is not enough). — mvmn, Jan 20 '19 at 12:38

score 110 · Answer 1 · edited Jul 29 '13 at 18:52

110

You should use DecimalFormat("0.#")

For 4.3000

Double price = 4.3000;
DecimalFormat format = new DecimalFormat("0.#");
System.out.println(format.format(price));

output is:

4.3

In case of 5.000 we have

Double price = 5.000;
DecimalFormat format = new DecimalFormat("0.#");
System.out.println(format.format(price));

And the output is:

edited Jul 29 '13 at 18:52

angelatlarge

answered Jan 07 '13 at 22:16

Marcin Szymczak

6

this fails the case of `5.0` becoming `5`, as it will always add a `.0` to the end of numbers. – Peter Elliott Jan 07 '13 at 22:25
2

Thank you for Your comment. Now I have figured out that I should have used 0.#. – Marcin Szymczak Jan 07 '13 at 22:29
44

this fails in the case of `4.32` which becomes `4.3` – David Conrad Jan 30 '14 at 19:29
@DavidConrad yes, because it is specifying only one decimal digit precision – Chisko Feb 01 '17 at 05:34
14

@Chisko The question asks how to "remove trailing zeros". – David Conrad Feb 01 '17 at 05:42
But the description clarifies – Chisko Feb 01 '17 at 06:15
It fails, 4.300001 becomes 4.3 and if you want to convert it to double, it will add .0 again. – Mohit Rajput Jan 23 '19 at 07:11
be aware that the output is 4,3 and not 4.3 – JU5T1C3 Jan 25 '19 at 09:02
3

A double type can't really do this. If you're willing to switch to BigDecimal, [here's the solution](https://stackoverflow.com/a/11284983/365837). – Rok Povsic Apr 15 '19 at 11:36
But how to be with values like 0.0005000 (must shown as 0.0005)? – fHate Jun 15 '20 at 10:50

score 7 · Accepted Answer · edited Feb 24 '14 at 08:30

7

  double answer = 5.0;
   DecimalFormat df = new DecimalFormat("###.#");
  System.out.println(df.format(answer));

edited Feb 24 '14 at 08:30

Jay

answered Jan 07 '13 at 22:11

soniccool

13

Won't this round the numnber like in case of 5.000001 – VikrantY Jun 15 '14 at 20:40
53

It does and that's why this is wrong... – Mostafa Zeinali Mar 03 '15 at 05:42

score 1 · Answer 3 · answered Jan 07 '13 at 22:09

1

Use a DecimalFormat object with a format string of "0.#".

answered Jan 07 '13 at 22:09

dashrb

17

this fails in the case of 4.32 which becomes 4.3 – narancs Mar 31 '16 at 12:50
1

fair point, although the OP didn't indicate how many places were desired. I can't think of a good reason to truncate trailing 0's but keep non-zeros as far as they are printable. IMHO, when printing a double, the code should specify the desired number of digits of precision (the number of #'s after the period). – dashrb Apr 13 '16 at 13:59
1

@Karoly DecimalFormat df = new DecimalFormat("###.##"); df.setRoundingMode(RoundingMode.HALF_UP); System.err.println(df.format(4.325)); System.err.println(df.format(4.30)); System.err.println(df.format(4.00)); – Uncle Iroh Jun 30 '16 at 16:13
2

@dashrb The OP was very explicit about what he wanted. He wants to remove trailing zeroes. Do you understand what the word "trailing" means? – Peter Schorn Sep 12 '20 at 01:06
@UncleIroh FYI this provides correct solution even after removing the RoundingMode.HALF_UP but keeping #.### – Prabhat Gaur Jan 13 '21 at 18:04
"0.##" will return 4.32 and not round off value. – xiang Apr 18 '23 at 03:17

3 Answers3