Formatting a BigInteger

[Luigi Plinge]

Hi,

I've searched the interwebs but can't find how to format the output of a BigInteger with commas.

If it were an integer I'd do

System.out.printf( "%, d", number );

but I'm not sure how to do it for a BigInteger (or a long for that matter).

[Mike Simmons]

Have you tried using the exact same code?

This is a subtle point, but when the JavaDocs for Formatter talk about "integer" or "integral" types, they don't just mean int. The term actually includes byte, short, int, long, all the wrapper classes for those primitive types, and BigInteger. In short, all standard numeric data types in Java except those for floating-point numbers. So 'd' can be applied to all of these.

[Luigi Plinge]

Wow, it works! I'm reading Head First Java and it doesn't mention longs or BigIntegers.

Thanks!