Truncate a float and a double in java

Question

I want to truncate a float and a double value in java.

Following are my requirements: 1. if i have 12.49688f, it should be printed as 12.49 without rounding off 2. if it is 12.456 in double, it should be printed as 12.45 without rounding off 3. In any case if the value is like 12.0, it should be printed as 12 only.

condition 3 is to be always kept in mind.It should be concurrent with truncating logic.

Take a look at: http://stackoverflow.com/questions/1976809/are-there-any-functions-for-truncating-a-double-in-java — BeRecursive, Apr 26 '12 at 11:36
Formatted printing is not the same thing as truncation. Truncation alters the data value. Your use of the term “truncate” is incorrect and misleading. I suggest you edit the title and body of your Question appropriately. For those readers looking for true truncation, see [*Are there any functions for truncating a double in java?*](https://stackoverflow.com/q/1976809/642706) as [commented by BeRecursive](https://stackoverflow.com/questions/10332546/truncate-a-float-and-a-double-in-java#comment13305233_10332546). — Basil Bourque, Dec 30 '20 at 08:27

score 27 · Accepted Answer · answered Apr 26 '12 at 11:51

27

try this out-

DecimalFormat df = new DecimalFormat("##.##");
df.setRoundingMode(RoundingMode.DOWN);
System.out.println(df.format(12.49688f));
System.out.println(df.format(12.456));
System.out.println(df.format(12.0));

Here, we are using decimal formatter for formating. The roundmode is set to DOWN, so that it will not auto-round the decimal place.

The expected result is:

12.49
12.45
12

answered Apr 26 '12 at 11:51

Kshitij

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Localization applies to the example. Depending on the default locale the output would be 12,49 for example. – Marcelo Benites Sep 15 '15 at 18:04

score 4 · Answer 2 · answered Aug 01 '12 at 18:46

4

double d = <some-value>;
System.out.println(String.format("%.2f", d - 0.005);

answered Aug 01 '12 at 18:46

Prizoff

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score 4 · Answer 3 · edited Aug 18 '17 at 09:45

4

I have the same problem using Android, you can use instead:

DecimalFormat df = new DecimalFormat("##.##");
df.setRoundingMode(RoundingMode.DOWN);

but for this API Level 9 is required.

Another fast solution is:

double number = 12.43543542;
int aux = (int)(number*100);//1243
double result = aux/100d;//12.43

edited Aug 18 '17 at 09:45

enkara

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answered Aug 11 '13 at 13:34

titusfx

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score 2 · Answer 4 · edited May 07 '14 at 06:49

2

take a look with DecimalFormat() :

DecimalFormat df = new DecimalFormat("#.##");
DecimalFormatSymbols dfs = new DecimalFormatSymbols();
dfs.setDecimalSeparator(',');
df.setDecimalFormatSymbols(dfs);

edited May 07 '14 at 06:49

Gwenc37

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answered Apr 26 '12 at 11:40

revo

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Change it to use `#` instead of `0` and it would work as specified. – Dunes Apr 26 '12 at 11:53

score 1 · Answer 5 · edited May 06 '14 at 14:42

1

Check java.math.BigDecimal.round(MathContext).

edited May 06 '14 at 14:42

Gwenc37

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answered Apr 26 '12 at 11:37

Torben

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That method doesn't seem to exist? [API docs](http://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html) – Eddie Curtis Apr 03 '15 at 08:12
@jimmycarr http://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html#round(java.math.MathContext) – Torben Apr 07 '15 at 09:19
Wow...how did I miss that? Thanks @Torben – Eddie Curtis Apr 07 '15 at 11:14

score 0 · Answer 6 · answered Apr 26 '12 at 11:47

0

Try using DecimalFormat and set the RoundingMode to match what you need.

answered Apr 26 '12 at 11:47

ChadNC

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Truncate a float and a double in java

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