iPhone应用程序中的NSString和stringWithString存在问题

谢谢

    NSString *addChar = nil; 

    NSString *fullname =  (NSString *)ABRecordCopyCompositeName(record);
    addChar = [[NSString stringWithString: [[fullname substringToIndex:1] capitalizedString]] retain];

    [fname release];

    NSMutableArray *array = [app_contacts objectForKey:addChar]; // lookup if key exists

    if (array == nil) // if nothing in key, create new array
    {
           NSLog(@"array empty"); 
           NSMutableArray *newarray = [[NSMutableArray alloc] init];
           [newarray insertObject:one_person atIndex:0];
           [app_contacts setValue:newarray forKey:addChar];
           [newarray release];
    }
    else
    {
           NSLog(@"array not empty");
           [array addObject:one_person];
           [app_contacts setValue:array forKey:addChar];
    }

    [addChar release];