Question

I am working on converting a plain tableview to a sectioned tableview. I would like the section titles to be the first letter for the items in the section.

This is what I have so far in my titleForHeaderInSection method:

NSSortDescriptor *sortDescriptor;
sortDescriptor = [[[NSSortDescriptor alloc] initWithKey:@"Name"
                                              ascending:YES] autorelease];
NSArray *sortedArray;
NSMutableArray *commonNameArray = [tableDataSource valueForKey:@"Name"];

NSArray *uniquearray;
uniquearray = [[NSSet setWithArray:commonNameArray] allObjects];
sortedArray = [uniquearray sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];

This code removes the duplicate titles and sorts the list alphabetically. Now I just need to convert the strings in the array to the first letters only. What is the best way to go about this?

Answer 1

NSMutableSet *firstCharacters = [NSMutableSet setWithCapacity:0];
for( NSString *string in [tableDataSource valueForKey:@"Name"] )
    [firstCharacters addObject:[string substringToIndex:1]];

NSArray *uniquearray = [[firstCharacters allObjects] sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];