Getting a double[] row array of a double[,] rectangular array

Question

Suppose you have an array like:

double[,] rectArray = new double[10,3];

Now you want the fouth row as a double[] array of 3 elements without doing:

double[] fourthRow = new double[]{rectArray[3,0],
                                  rectArray[3,1], 
                                  rectArray[3,2]};

Is it possible someway? Even using a Marshal.Something approach?

Thanks!

Answer 1

Why not make a generic extension method?

    public static T[] GetRow<T>(this T[,] input2DArray, int row) where T : IComparable
    {
        var width = input2DArray.GetLength(0);
        var height = input2DArray.GetLength(1);

        if (row >= height)
            throw new IndexOutOfRangeException("Row Index Out of Range");
        // Ensures the row requested is within the range of the 2-d array


        var returnRow = new T[width];
        for(var i = 0; i < width; i++)
            returnRow[i] = input2DArray[i, row];

        return returnRow;
    }

Like this all you have to code is:

array2D = new double[,];
// ... fill array here
var row = array2D.GetRow(4) // Implies getting 5th row of the 2-D Array

This is useful if you're trying to chain methods after obtaining a row and could be helpful with LINQ commands as well.