How to put 2 poins in a 2d array in C#

Question

I have class point with properties and I need to put an x and y point in 2d array and it s something like this:

Point[,] p = new Point [100,2];

Main
p[0,0].x = Convert.ToInt32(textbox1.text)
// how would this inicialization be correct ???

Answer 1

Doesn't it work as:
Point[][] p = new Point(); ?
And changing values as:
p[x][y] = z;

Answer 2

Its throws me exception null reference 'Object reference not set to an instance of an object,

Answer 3

maybe you should add parentheses within the creation:
Point[,] p = new Point([100, 2])