C#_OOP_Inheritance_Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace App1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(Human.PI);
            Console.WriteLine(Human.onlyRead);

           // int counter = 0;
            Human person1 = new Human("Stoyan", 50);
            // counter++;
            // Console.WriteLine(person1.onlyRead);
            Human person2 = new Human(20, "Ivan", "John", "Bruce");
            // counter++;
            Human person3 = new Human();
            // counter++;

            // Console.WriteLine("My name is {0}. I am {1} yers old.", person1.Name, person1.Age);
            // Console.WriteLine("My name is {0}. I am {1} yers old.", person2.Name, person2.Age);

            Human.Nationality = "German";

            person1.IntroduceYoutSelf("verbous");
            person2.IntroduceYoutSelf();
            Console.WriteLine("My friend is {0}.", person2.GetFriend(0));
            person3.IntroduceYoutSelf();

            IncreasePopulation();

            Student student1 = new Student("Kirsten", 25, 2345);
            Athlete athlete1 = new Athlete("Christian", 26, "futbol");

            student1.IntroduceYoutSelf();
            athlete1.IntroduceYoutSelf();

            Executor exec1 = new Executor(student1);
            exec1.MakeHimSpeak();


            Console.WriteLine("The population {0}", Human.counter);

            Console.WriteLine("The National Income is {0}", Human.CalculateNationalIncome());

            Console.WriteLine("Hello World!");
            Console.Read();
        }

        public static void IncreasePopulation()
        {
            Human person1 = new Human("Bruce", 15);
        }
    }
}