int rows = 5, column = 7;
int[][] arr = new int[rows][column];
//2D arrays are row major, so always row first
for (int row = 0; row < arr.length; row++)
{
for (int col = 0; col < arr[row].length; col++)
{
arr[row][col] = 5; //Whatever value you want to set them to
}
}