How to sort NSMutableArray? Code review needed - objective-c

Question

Good evening.
This code works. It sorts an array of cards by both Suit and Card Value. It is also very much brute force. Can you recommend a better way? Does Objective-C help dealing with a situation where object being sorted itself has multiple fields, on which sorting depends?
-(void) sort: (NSMutableArray *) deck {
NSUInteger count = [deck count];
Card *thisCard;
Card *nextCard;
int this;
int next;
BOOL stillSwapping = true;
while (stillSwapping) {
stillSwapping = false;
for (NSUInteger i = 0; i < count; ++i) {
this = i;
next = i+1;
if (next < count) {
thisCard = [deck objectAtIndex:this];
nextCard = [deck objectAtIndex:next];
if ([thisCard suit] > [nextCard suit]) {
[deck exchangeObjectAtIndex:this withObjectAtIndex:next];
stillSwapping = true;
}
if ([thisCard suit] == [nextCard suit]) {
if ([thisCard value] > [nextCard value]) {
[deck exchangeObjectAtIndex:this withObjectAtIndex:next];
stillSwapping = true;
}
}
}
}
}
}

Answer 1

You have several options.
Perhaps the simplest is to define the method -compare: on Card, which returns an NSComparisonResult. This is preferable if sorting by suit and value is the "standard" way to sort a Card. If you've done this, then your entire sorting method can be turned into
[deck sortUsingSelector:#selector(compare:)];
If you don't want to do this, you can use an array of NSSortDescriptors, one for suit and one for value.
[deck sortUsingDescriptors:[NSArray arrayWithObjects:[NSSortDescriptor sortDescriptorWithKey:#"suit" ascending:YES], [NSSortDescriptor sortDescriptorWithKey:#"value"] ascending:YES], nil]];
If this doesn't work for whatever reason, you could try -sortUsingComparator:
[deck sortUsingComparator:^NSComparisonResult(Card *obj1, Card *obj2) {
int suit1 = [obj1 suit];
int suit2 = [obj2 suit];
if (suit1 > suit2) {
return NSOrderedDescending;
} else if (suit1 < suit2) {
return NSOrderedAscending;
} else {
id value1 = [obj1 value];
id value2 = [obj2 value];
if (value1 > value2) {
return NSOrderedDescending;
} else if (value1 < value2) {
return NSOrderedAscending;
} else {
return NSOrderedSame;
}
}
}