How to iterate NSArray of results into separate arrays

Question

I am using Parse for data storage. I create a query for my Game Turn Scores which return an array in a callback like this:

(
"<GameTurnScore:ipPd3tKRc1:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 1;\n    TurnDifficulty = 0;\n    TurnNumber = 1;\n    TurnScore = 500;\n    UserRef = \"<PFUser:e3Wyo4JaKC>\";\n}",
"<GameTurnScore:AendjA9Yzq:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 6;\n    TurnDifficulty = 1;\n    TurnNumber = 2;\n    TurnScore = 48;\n    UserRef = \"<PFUser:UgkZDtDsVC>\";\n}",
"<GameTurnScore:ZTNmSkGae1:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 8;\n    TurnDifficulty = 2;\n    TurnNumber = 3;\n    TurnScore = 60;\n    UserRef = \"<PFUser:e3Wyo4JaKC>\";\n}",
"<GameTurnScore:8QbcznSa1u:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 3;\n    TurnDifficulty = 1;\n    TurnNumber = 4;\n    TurnScore = 99;\n    UserRef = \"<PFUser:UgkZDtDsVC>\";\n}",
"<GameTurnScore:Mj6LmdE5LY:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 8;\n    TurnDifficulty = 0;\n    TurnNumber = 5;\n    TurnScore = 60;\n    UserRef = \"<PFUser:e3Wyo4JaKC>\";\n}",
"<GameTurnScore:qeDWt7KFK2:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 12;\n    TurnDifficulty = 1;\n    TurnNumber = 6;\n    TurnScore = 24;\n    UserRef = \"<PFUser:UgkZDtDsVC>\";\n}",
"<GameTurnScore:RMRYi9fkUu:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 1;\n    TurnDifficulty = 2;\n    TurnNumber = 7;\n    TurnScore = 500;\n    UserRef = \"<PFUser:e3Wyo4JaKC>\";\n}",
"<GameTurnScore:Fd78iI8NGo:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 6;\n    TurnDifficulty = 1;\n    TurnNumber = 8;\n    TurnScore = 48;\n    UserRef = \"<PFUser:UgkZDtDsVC>\";\n}",
"<GameTurnScore:qioVUqmbEB:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 1;\n    TurnDifficulty = 2;\n    TurnNumber = 9;\n    TurnScore = 500;\n    UserRef = \"<PFUser:e3Wyo4JaKC>\";\n}",
"<GameTurnScore:iFLS39GqLM:(null)> {\n    GameRef = \"<Game:jGBok5ZiXM>\";\n    TotalGuesses = 1;\n    TurnDifficulty = 1;\n    TurnNumber = 10;\n    TurnScore = 300;\n    UserRef = \"<PFUser:UgkZDtDsVC>\";\n}"
)  

I then need to separate these scores into two separate arrays. At present I separate based on the user but I would like to separate these based on the TurnNumber.

The specific part I am unsure about is inserting an emtpy index or [NSNull null] into an index if a turn number does not exist.

For example, I have two new NSArrays called scoreBlock1 and scoreBlock2. If turn number 3 is missing I would like the following in scoreBlock1.

turnNumber1
NSNull null
turnNumber5
turnNumber7
turnNumber9

What is the best way to iterate the results array to achieve this?

Answer 1

You can use [array addObject:[NSNull null]] to insert a null into an array.

You can later test for the presence of a null value using [object isKindOfClass:[NSNull class]]