Question

Im trying to implement a 2D array class using List of Lists. Can someone please help me to implement a get function similar to T this[int x, int y] function below to get all the elements in a column given by [int x,:] where x is the column. Returning as an array would be fine.

public class Matrix<T>
{
    List<List<T>> matrix;

    public Matrix()
    {
        matrix = new List<List<T>>();
    }

    public void Add(IEnumerable<T> row)
    {
        List<T> newRow = new List<T>(row);
        matrix.Add(newRow);
    }

    public T this[int x, int y]
    {
        get { return matrix[y][x]; }
    }
}

Answer 1

Or:
return matrix.Select(z=>z.ElementAtOrDefault(x));