Check a matrix's value in a certain position and compare it to another

Im trying to make a function that will take a matrix as a paramater, then display this array to the console using diffrent symbols. To acomplish this im trying to check the value of Matrix[1,1] and compare it to see what symbol needs to be displayed. This is all using C#.

I tried to use this code to read a matrix and display a symbol to the console

        // Displays the gameboard requested
        public static void DisplayBoard(int[,] gameboard)
        {
           int boardLength = gameboard.GetLength(0); // Gets the size of the board and stores it
            // Displays the game board to the console as a square with correct symbols
            for (int i = 1; i <= boardLength; i++)
            {
                for (int j = 1; j <= boardLength; j++)
                {
                    // Checks the arrays position and changes the symbol based on its value
                    if (gameboard[i, j] == 1) // Player one X
                    {
                        Console.Write("X");
                    }
                    else if (gameboard[i, j] == 2) // Player 2 O
                    {
                        Console.Write("O");
                    }
                    else // default empty square
                    {
                        Console.Write("-");
                    }
                    
                }
                Console.WriteLine(string.Empty);
            }
        }

I Expected this to read the matrixs value and run the for loops, if the value in matrix[1,1] is equal to 0 i expected it to be throw to the else statement and print "-" to the console, is equal to 1 itll print "x" and 2 will be a "o". It would then move to the next row and repeat the loops till the array has been translated to the console.
What happens is im displayed the System.IndexOutOfRangeException: error on the first line with an if statement, if (gameboard[i, j] == 1),

Try changing your for loops. The index starts at 0, not 1.

for (int i = 0; i < boardLength; i++)

This is mainly an issue of the way C# works with arrays of nested arrays and the oddities of working with them (index starts at 0, length starts at 1). You're calling the length which contains all ints in the array regardless of how deeply nested they are, whereas you need to be calling the rank which defines the number of nested arrays in your array. Remember this is a 2d array, so we can't count from a single "length" to get it to work.

So for example, you might end up calling gameboard[1,9] when the first nested array doesn't contain 9 elements... and this gets your issue!

You can fix this issue by modifying your syntax as below to consider both length and width of your array where all nested arrays are of the same size:

        public static void DisplayBoard(int[,] gameboard)
        {
           int boardLength = gameboard.Rank - 1;
           int boardWidth = gameboard.GetLength(0) / boardLength;
            for (int i = 0; i <= boardLength; i++)
            {
                for (int j = 0; j <= boardWidth; j++)
                {
                    // Checks the arrays position and changes the symbol based on its value
                    if (gameboard[i, j] == 1) // Player one X
                    {
                        Console.Write("X");
                    }
                    else if (gameboard[i, j] == 2) // Player 2 O
                    {
                        Console.Write("O");
                    }
                    else // default empty square
                    {
                        Console.Write("-");
                    }
                    
                }
                Console.WriteLine(string.Empty);
            }
        }

Here we calculate the length and width and then use these two parts to actually iterate through our 2d array.