stackalloc Demo
using System; class MainEntryPoint { static unsafe void Main() { Console.Write("How big an array do you want? \n> "); string userInput = Console.ReadLine(); uint size = uint.Parse(userInput); long* pArray = stackalloc long[(int)size]; for (int i = 0; i < size; i++) pArray[i] = i * i; for (int i = 0; i < size; i++) Console.WriteLine("Element {0} = {1}", i, *(pArray + i)); } }