Round doubles in Objective-C

Question

I have double number in a format like 34.123456789. How can I change it to 34.123?

I just want 3 digits after the decimal point.

Answer 1

You can use:

#include 
:
dbl = round (dbl * 1000.0) / 1000.0;

Just keep in mind that floats and doubles are as close an approximation as the underlying type can provide. It may not be exact.