Similar to comma separated thousand NSString stringWithFormat but with a specific use case.
How do I insert a comma (,) after every third digit?
Some cases:
The results are expected regardless of locale or any other circumstance.
What I needed was not something that would care for the locale of a user, and with that it was just easier to do some string juggling. If someone cares I could dig up that code...
If you however DO care for locales, go with the other answer of Dave DeLong. Technically however it does not answer the question.