why index out of 2D array`s range which set capacity

Could you edit your code in a readable format ?

And give more complete code.

If you fear so much someone steals you code, you'd better off not ask for support !

I agree with what you said, but I just noticed that the bug is obvious — or would have been, if the code was formatted better.

If 'cells' is an array of 'm' arrays of 'n' elements, then the 'for' loops need to be like this:

for i in 0..<m {

for j in 0..<n {

That is, ..< rather than ... .

GameScene: SKScene{

var board = Board( )

override func didMove( to view: SKView){

self.setCells () }

func setCells( ){

self.board.cells = Array(repeating: Array(repeating: nil, counts: n), counts: m) } }

Board: GKGameModel{

var cells: [ [ SKSpriteNode? ] ] = [ ]

func isWin(for player: GKGameModelPlayer) {

for i in 0...m{

for j in 0...n{

if let node = self.cells[ i ] [ j ] { } }} }

/. / appear "fatal error: index out of range.

why appear fatalerror after i have set 2D array`s capability.

Quincey gave you the solution.

For formatting, use the <> tool: And take care of your identation, it is hardly readable.

GameScene: SKScene{
       var board =  Board( )

    override func didMove( to view: SKView){
             self.setCells ()  }

            func setCells( ){
              self.board.cells = Array(repeating: Array(repeating: nil, counts: n), counts: m) }  
             }    

class Board: GKGameModel {
   var cells: [ [ SKSpriteNode? ] ] = [ ]

     func isWin(for player: GKGameModelPlayer) {
       for i in 0..           for j in 0..                 if let node = self.cells[ i ] [ j ] {    }  
               }
          } 
     }
      // appear "fatal error: index out of range.     

the fatalerror appear in for loop:

for i in 0...(m - 1){

for j in 0...(n - 1){

if let node = self.cells[ i ][ j ] { } }

/. / appear "fatal error: index out of range"

so i don` t know how it come out and how adjust. thanks for your appriciation.

what is the value of m ? of n ?

Add a print statement to trace exactly when it occurs

     for i in 0...(m - 1) {
         for j in 0...(n - 1) {
               print(i, j)
                if let node = self.cells[ i ][ j ] { 
                    print("This one OK", i, j) 
          }    

}

I am surprised that this statement works:

self.board.cells = Array(repeating: Array(repeating: nil, counts: n), counts: m) }

because the syntax is count, not counts

Did you copy the actual code or did you retype it ?

in the for loop the "fatal error: index out of range" not disappear and crash process, i don`t know how amend to remove "fatal error".

( Int m, n ) can set 9 and 10, or other.

GameScene : SKScene {

var board = Board ( )

func setCells ( ) {

self.board.cells = Array(repeating : Array ( repeating : nil , count : 10 ) , count : 9 )

}

Board : GKGameModel {

var cells : [ [ SKSpriteNode ? ] ] = [ ]

func isWin( GKGameModelPlayer ) {

for i in 0 . . . 8 {

for j in 0 . . . 9 {

if let node = self . cells [ i ] [ j ] { / / appear " fatal error: index out of range"

}

}

} }

why appear "index out of range ", the 2D array` s capability has been set, why out of range.

Could you add the print I asked you :

     for i in 0...(m - 1) {
         for j in 0...(n - 1) {
               print(i, j)
                if let node = self.cells[ i ][ j ] {  
                    print("This one OK", i, j)  
          }     
}

And report exactly what you get on console (copy and paste).

As you don't show more code, it is impossible to know where you call the different func.

When do you call isWin ?

Is it after didMove ?

Please show the code, do not only paraphrase your code, it is useless.

Unless I get some code to understand the context, I cannot continue to investigate and spend my time on this.

as your idea, i have tryed, the first function print ( ) can be fine, but process to" if let node = self.cells [ i ][ j ]" appear fatalerror.

when implement on xcode`s simulator ipad pro 12.9 , process crash showing below:

for i in 0...(m - 1){

for j in 0...(n - 1) {

print( i, j )

if let node = self . cells [ i ][ j ] { /. /. appear "fatal error: index out of range " why appear fatal error, i can not explain.

print("ok", i , j )

}

}

}

GameScene: SKScene{

var board = Board ( )

var strategy: GKMonteCarloStrategist? / / this object calls func isWin( ) automatically.

override didMove( ) {

self. setCells ( ) / / self.board.cells = Array( repeating: ( repeating: nil, count : n ), count: m )

}

}

other code has nothing with variable cells of Board, the property capability of cells has been set ( Int m, n ).

You did not reply.

What do you get on console for the print statement ?

Do you get ?

0 0

0 1

…

Or do you crash before.

In addition, Why do not you copy the exact code ?

The following will not compile because of space around dot. So, this is not the code but something you typed in the forum.

if let node = self . cells [ i ][ j ]