using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication2
{
    public struct SudokoGrid {
        public int[,] grid;
        public SudokoGrid Init() {
            return new SudokoGrid()
            {
                grid = new int[9, 9]
            };
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            SudokoGrid k = new SudokoGrid();
            k = k.Init();
            for (int i = 0; i < 9; i++) {
                for (int j = 0; j < 9; j++) {
                    Console.Write(k.grid[i, j]);
                }
                Console.Write("\n");
            }
        }
    }
}

Output:

000000000
000000000
000000000
000000000
000000000
000000000
000000000
000000000
000000000
Press any key to continue . . .