Stack ADT - Array Implementation

// List ADT - Array implementation of Stack ADT
// Written by   : Jun Y. Ercia
// Date created : 7 September 2016

using System;

namespace Stack_Array_Implementation
{
     class Stack
     {
          private Object[] stack;
          int top;
          int size;

          public Stack(int size)
          {
               this.size = size;
               stack = new Object[size];
               top = 0;
          }

          public int Count
          {
               get { return top; }
          }

          public bool isEmpty()
          {
               return top == 0;
          }

          public bool isFull()
          {
               return top == size;
          }

          public void push(Object item)
          {
               if (!isFull())
               {
                    stack[top++] = item;
               }
               else
               {
                    Console.Write("Error! Stack Overflow.");
               }
          }

          public Object pop()
          {
               if (!isEmpty())
               {
                     return stack[--top];
               }
               else
               {
                    Console.Write("Error! Stack Underflow.");
                    return "";
               }
          }

          public Object peek()
          {
               if (!isEmpty())
               {
                    return stack[top - 1];
               }
               else
               {
                    Console.Write("Error! Stack Underflow.");
                    return "";
               }
          }
     }
}

-------------------------------------------------------------------------------------------------------------

Driver Program Using Stack Class

using System;

namespace Sorted_List
{
     class Program
     {
          static void Main(string[] args)
          {
               List fruits = new List(5);      //create new list of fruits

               fruits.insert(0, "Banana");    //insert at position 0
               fruits.insert(0, "Apple");     //insert at position 0
               fruits.insert(1, "Grape");     //insert at position 1
               fruits.print();                //print Apple, Grape, Banana

               fruits.insertAtFront("Guava"); //insert at the front of the list
               fruits.insertAtEnd("Orange");  //insert at the end of the list
               fruits.insert(0, "Mango");      //Error! list is full
               fruits.print();                //print Guava, Apple, Grape, Banana, Orange

               Console.WriteLine(fruits.front()); //print "Guava"
               Console.WriteLine(fruits.tail()); //print "Orange"

               fruits.removeAt(0);            //remove "Guava"
               fruits.print();                //print  Apple, Grape, Banana, Orange

               fruits.removeAt("Grape");      //remove "Grape"
               fruits.print();                //print Apple, Banana, Orange

               fruits.makenull();             //make the list empty
               fruits.print();                //print "The List is Empty"
               Console.ReadKey();
          }
     }
}