Question

I have this code which works on numbers (distance) which allows me to sort by closest to farthest. However I would like to do something similar but instead sort alphabetically. So I need to sort self.names alphabetically essentially. Also, I’d like to eventually sort self.names alphabetically and if you have identical names then sort those by distance. Is this possible?

- (NSComparisonResult)sortByDistFromVor:(radiostations *)anObject
{

    if ([self.distFromVor doubleValue] < [anObject.distFromVor doubleValue]) {
        return NSOrderedAscending;
    } else if ([self.distFromVor doubleValue] > [anObject.distFromVor doubleValue]) {
        return NSOrderedDescending;
    }
    return NSOrderedSame;
}

Answer 1

String implements a comparison, so the radiostations class (whose name ought to be capitalized by convention) can implement it’s name comparison like this:

- (NSComparisonResult)sortByName:(radiostations *)anObject {

    return [self.name compare:anObject.name];
}

And to get a secondary sort as you described:

- (NSComparisonResult)sortByNameThenDistance:(radiostations *)anObject {

    NSComparisonResult result = [self sortByName:anObject];
    return (result == NSOrderedSame)? [self sortByDistFromVor:anObject] : result;
}