NSArray Methods

PeopleNSArrayMethods

- (NSString *)generatePartyList
{
    NSMutableArray *partyNamesArray = [[NSMutableArray alloc]init];
    
    for (Person *friend in self.friends){
        
        [partyNamesArray addObject:friend.name];
    }
    
    return [partyNamesArray componentsJoinedByString:@", "];
}

- (BOOL)removeFriend:(Person *)friend
{
    for (NSInteger i = 0; i < [self.friends count]; i++){
        
        if (self.friends[i] == friend){
            
            [self.friends removeObjectAtIndex:i];
            return YES;
        }
    }
    return NO;
}

- (NSArray *)removeFriends:(NSArray *)friends
{
    NSMutableArray *result = [[NSMutableArray alloc] init];
    
    for (Person *friend in friends){
        
        [self removeFriend:friend];
        [result addObject:friend];
    }
    
    return result;
}