Padding string to left

Question

How can one pad a string to left in objective c. E.g if I have an integer value of 6 I want it to be displayed as 06.

I use stringByPaddingToLength: but

Answer 1

+ (NSString *)formatValue:(int)value forDigits:(int)zeros {
    NSString *format = [NSString stringWithFormat:@"%%0%dd", zeros]; 
    return [NSString stringWithFormat:format,value];
}