How do I set the fill character for displaying numbers (Objective C)

Question

I'm trying to format a string to give me 2 characters for a number, no matter what its value. Right now, I have

[NSString stringWithFormat:@"%2d:%2d:%2d",h,m,s)];

and for the values 1, 2, 3, the output is

 1: 2: 3

How do I change the spaces to 0's ?

Answer 1

This is done the same as C's printf (see man 3 printf):

[NSString stringWithFormat:@"%02d:%02d:%02d",h,m,s];

(By the way, if you're trying to format dates or times, I'd suggest looking at NSDateFormatter.)