// StackTest.cs: Demonstrating class Stack.
using System;
using System.Collections;

public class StackTest
{
   public static void Main( string[] args )
   {
      Stack stack = new Stack(); // default Capacity of 10

      // create objects to store in the stack
      bool aBoolean = true;
      char aCharacter = '$';
      int anInteger = 34567;
      string aString = "hello";

      // use method Push to add items to (the top of) the stack
      stack.Push( aBoolean );
      PrintStack( stack );

      stack.Push( aCharacter );
      PrintStack( stack );

      stack.Push( anInteger );
      PrintStack( stack );

      stack.Push( aString );
      PrintStack( stack );

      // check the top element of the stack
      Console.WriteLine( "The top element of the stack is {0}\n",
                         stack.Peek() );

      // remove items from stack
      try
      {
         while ( true )
         {
            object removedObject = stack.Pop();
            Console.WriteLine( removedObject + " popped" );
            PrintStack( stack );
         } // end while
      } // end try
      catch ( InvalidOperationException exception )
      {
         // if exception occurs, output stack trace
         Console.Error.WriteLine( exception );
      } // end catch
   } // end Main

   // display the contents of a stack
   private static void PrintStack( Stack stack )
   {
       if (stack.Count == 0)
       {
           Console.WriteLine("stack is empty\n"); // the stack is empty
       }
       else
       {
           Console.Write("The stack is: ");

           // iterate through the stack with a foreach statement
           foreach (var element in stack)
           {
               Console.Write("{0} ", element); // invokes ToString
           }

           Console.WriteLine("\n");
       } // end else
   } // end method PrintStack
} // end class StackTest