CODEWITHSUNDEEP
javastringformattingdoublecurrency
fluffyBall
fluffyBall

Reputation: 23

making double readable by adding '.' , ',' , trimming (not rounding) so only 2 last digits possible?

I've been looking for a way to convert a double, which is big to a readable String. The double:

 double myValue = 1000000000000000.123456789;

Which when printed out gives me this:

 1.0000000000000001E15

The result im looking for would be this:

1.000.000.000.000.000,12

I've been searching for this for days but i couldn't find a solution for this unfortunately so i thought maybe i could ask here:) thanks for reading!

Upvotes: 0

Views: 31

Answers (1)

sprinter
sprinter

Reputation: 27986

If you are interested in setting your own separator characters (i.e. not using the default for your locale) then you can do the following:

DecimalFormatSymbols symbols = new DecimalFormatSymbols();
symbols.setGroupingSeparator('.');
symbols.setDecimalSeparator(',');
DecimalFormat format = new DecimalFormat("#,##0.00", symbols);
System.out.println(format.format(100000000000.123456789));

You also mentioned rounding in your question. Unfortunately that has nothing to do with the formatting at all - you are hitting the limit of precision for double in Java. A double is a 64 bit floating points which gives you 15-16 digits of precision. You can verify this by checking the following expression in Java: 1000000000000000.123456789 == 1000000000000000.1.

So, in reality what is happening is that once you have assigned your value to the myValue variable it has already been rounded. It doesn't matter how you format it from that point you won't get the precision back.

If you need greater precision than double you should look at BigDecimal that supports arbitrary precision.

Upvotes: 1

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