Stack

The stack is similar to a queue but the opposite, a stack is a First-in-Last-out or FiLo data structure. Think of a stack of cookies, you stack one on top of the other and when you go to eat your first cookie, it's the last one you put down. 

though a stack has several functions, the three main ones are:

• Push: adds an item to the top of the stack
• Pop: takes out the newest item from the top of stack
• Peek: looks at the newest item on the top of the stack.

Now let's look at a demo

using System.Collections;

namespace pav.stackExample;

class Program

{

    static void Main(string[] args)

    {

        Stack s = new Stack();

        s.Push(1);

        s.Push("two");

        s.Push("Three");

        s.Push(4);

        s.Push(5.0);

        while (s.Count > 0)

            Console.WriteLine(s.Pop());

    }

}

one thing to keep in mind is that peek an empty stack will through an exception.