Number Format (Comma Separation) as per locale

Question

I have a requirement to show a number value like 123456789.905 in the following format 123,456,789.90. But the comma separation changes depending on the locale selected in the phone (as if with US English selected comma separation is 3 places and if India English is selected it is like 12,34,56,789.90).

How can I format my Double?

Answer 1

So, java.text.NumberFormat doesn't slove the problem, unfortunately, but com.ibm.icu.text.NumberFormat does.

You can use this:

Double d = 123456789.905;
com.ibm.icu.text.NumberFormat format = com.ibm.icu.text.NumberFormat.getNumberInstance(new Locale("en", "in"));
format.setMinimumFractionDigits(2);
format.setMaximumFractionDigits(2);

System.out.println(format.format(d));

This outputs: 12,34,56,789.90.

Answer 2

For the generic case, use java.text.NumberFormat:

NumberFormat nf = NumberFormat.getInstance();
String formatted = nf.format(yourDoubleValue);

By default getInstance() returns a NumberFormat that is configured as appropriate for the current Locale. You can change the configuration yourself, too.

The "comma separation" is called "grouping".

For the specific case of grouping in an Indian currency format, see: Displaying Currency in Indian Numbering Format