Question

I’ve tried NSMutableDictionary however I don’t seem to be able to get an object by index.

Any ideas?

EDIT:
I’ve trying to create a uitableview sections object, which will store the header titles and be able to increment a counter for the rows. I need to be able to get the counter by index, counter value by title value.

Answer 1

Simplest way is to use 2 collections: dictionary for section infos (row numbers, countries etc) and array for section titles.

NSMutableDictionary *sectionInfos;
NSMutableArray *sectionTitles;

When you need a section info by sectionTitle:

NSDictionary *info = [sectionInfos objectForKey:sectionTitle];
int rowsCount = ((NSArray *)[info objectForKey:@"Countries"]).count;

When you need a section info by sectionIndex:

NSString *title = [sectionTitles objectAtIndex:sectionIndex];
NSDictionary *info = [sectionInfos objectForKey:title];
int rowsCount = ((NSArray *)[info objectForKey:@"Countries"]).count;

When you add a section, add sections info:

[sectionInfos setObject:info forKey:sectionTitle];

and a title to array, so infos and titles will be in sync.

[sectionTitles addObject:sectionTitle];

UPDATE: if the only info needed for section is number of rows:
UPDATE2: added types.

NSMutableDictionary *sectionRowCounts;
NSMutableArray *sectionTitles;

Rows count by sectionTitle:

int rowCount = [[sectionRowCounts objectForKey:sectionTitle] intValue];

Rows count by sectionIndex:

NSString *title = [sectionTitles objectAtIndex:sectionIndex];
int rowCount = [[sectionRowCounts objectForKey:title] intValue];

Adding a section:

[sectionRowCounts setObject:[NSNumber numberWithInt:rowCount] forKey:sectionTitle];
[sectionTitles addObject:sectionTitle];