csharp array 2d code example

Example: how to use a 2d array in csharp

int[,] arr = new int[3,3];//declaration of 2D array  
int[,] arr = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 }}//another way to declare
arr[1,2]=20; //access to the array