How to split NSArray into UITableView sections alphabetically

Question

I have having trouble using an indexed table with section headers. Currently I have the indexes down the right hand side and I have the section headers showing correctly, th

Answer 1

Just in case you have custom objects , little modification in @Leo

NSMutableSet *firstCharacters = [NSMutableSet setWithCapacity:0];
        for( ETUser *user in self.follwings){
            [firstCharacters addObject:[[user.name substringToIndex:1] uppercaseString]];
        }
        NSArray *allLetters = [[firstCharacters allObjects] sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
        int indexLetter = 0;
        NSMutableArray *separeNamesByLetters = [NSMutableArray new];


        for (NSString *letter in allLetters) {

            NSMutableDictionary*userBegeinsWith = [NSMutableDictionary new];

            [userBegeinsWith setObject:letter forKey:@"letter"];

            NSMutableArray *groupNameByLetters = [NSMutableArray new];

            NSString *compareLetter1 = [NSString stringWithFormat:@"%@", allLetters[indexLetter]];

            for (ETUser *user in self.follwings) {

                NSString *compareLetter2 = [[user.name substringToIndex:1] uppercaseString];

                if ( [compareLetter1 isEqualToString:compareLetter2] ) {

                    [groupNameByLetters addObject:user];
                }
            }
            indexLetter++;
            [userBegeinsWith setObject:groupNameByLetters forKey:@"list"];
            [separeNamesByLetters addObject: userBegeinsWith];
        }

        self.follwings = [[NSMutableArray alloc]initWithArray:separeNamesByLetters];