How to convert numbers into text?

Question

I have been learning Objective-C with the Kochan book and I can\'t figure out how to do this exercise program. Only odd numbered exercises are listed online and this one is

Answer 1

As a learning exercise, I modified Dave's code:

+(NSString*)doIt:(NSString*)inString delimiter:(NSString*)delimiter{
    NSNumberFormatter *f = [[NSNumberFormatter alloc] init];
    [f setNumberStyle:NSNumberFormatterSpellOutStyle];
    NSMutableString* outString= [[NSMutableString alloc]init];
    for (int i=0; i< [inString length]; i++) {
        unsigned char oneChar= [inString characterAtIndex:i];
        if (oneChar>47 && oneChar<58) {
            NSString* temp=[f stringFromNumber:[NSNumber numberWithUnsignedChar:oneChar-48]];
            [outString appendFormat:@"%@",temp];
            [outString appendString:delimiter];
        }
    }
    [f release];
    [outString autorelease];
    return outString;
}