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]]
質問
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?
解決
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]]