Regexp matching group not working on objective-c

Question

I'm trying to get from this string: 5556007503140005 Two strings. "555600750314" and "0005"

I'm Using the regexp ^([a-z0-9]*)([0-9]{4})$ that works fine on the regexp tools, but when i use this on my code I only get 1 match.

this is the code

-(NSDictionary *)parse_barcode:(NSString *)barcode {
    NSString *regexp = @"^([a-z0-9]*)([0-9]{4})$";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regexp];

    if ([predicate evaluateWithObject:barcode]) {
        NSError *error;

        NSRegularExpression *regular_exp = [NSRegularExpression regularExpressionWithPattern:regexp options:0 error:&error];

        NSArray *matches = [regular_exp matchesInString:barcode options:0 range:NSMakeRange(0, [barcode length])];

        for (NSTextCheckingResult *match in matches) {
            NSLog(@"match %@ :%@",[barcode substringWithRange:[match range]], match);
        }

    }
    return nil;
}

But the match is always the entire string (Barcode)

Answer 1

You get the right match, you are just not printing them correctly. You need to use numberOfRanges to get the individual groups (ie sections enclosed in parentheses), and then call rangeAtIndex: for each group, like this:

for (NSTextCheckingResult *match in matches) {
    for (int i = 0 ; i != match.numberOfRanges ; i++) {
        NSLog(@"match %d - %@ :%@", i, [barcode substringWithRange:[match rangeAtIndex:i]], match);
    }
}