无法在C＃中将值添加到多维数组

Question

I am new to C#. I am trying to make a matrix calculator but first I need the user to give me the size of and the contents of said matrix. I have 2 classes.

First class is as follows:

class Assignment1
{
    static void Main(string[] args)
    {
        Console.Write("Please enter the number of rows in the matrix: ");
        int row = int.Parse(Console.ReadLine());

        Console.Write("Please enter the number of columns in the matrix: ");
        int columns = int.Parse(Console.ReadLine());

        MatrixN matrix =new MatrixN(row, columns);

        int i = 0;
        for (double x = 0; x < row; x++)
        {
            for(double y = 0; y < columns; y++)
            {

                if(i == 0)
                {
                    Console.Write("Enter first value of the matrix: ");
                    matrix[x, y] = double.Parse(Console.ReadLine());
                    i++;
                }
                else if (i == row * columns)
                {
                    Console.Write("Enter last value of the matrix: ");
                    matrix[x, y] = double.Parse(Console.ReadLine());
                    i++;
                }
                Console.Write("Enter nest value of the matrix: ");
                matrix[x, y] = double.Parse(Console.ReadLine());
                i++;
            }
        }
    }
}

Second class is:

 class MatrixN
{

    double[,] m;

    public MatrixN(int row, int column)
    {
        m = new double[row, column];
    }

I keep getting the error: cannot apply indexing with [] to an expression of MatrixN for the code

matrix[x, y] = double.Parse(Console.ReadLine());

Any help would be greatly appreciated. Thank you.

Answer 1

matrix is a variable of type MatrixN . The type MatrixN does not support the subscription/indexing operation, so you cannot access the value matrix[i, j] , nor set the value matrix[i, j] = v; .

You can either expose the m member variable of the MatrixN class (by making it public), and set/access the value of matrix.m , or write your own index operator:

class MatrixN {
   private double[,] inner;
   public double this[int x, int y] {
       get { return inner[x, y]; }
       set { inner[x, y] = value; }
   }
}