using System;

public class Program

{

    public static void Main()

    {

        var firstPerson = new Person("Max", "Mustermann");

        var secondPerson = new Person("Maxi", "Musterfrau");

        var thirdPerson = new Person("Max2", "Mustermann2", Guid.NewGuid());

        var fourthPerson = new Person("Maxi2", "Musterfrau2", default(Guid));

        var personsHaveIdenticalIdentities = firstPerson.ArePersonEqual(secondPerson);

        Console.WriteLine("firstPerson.Identity == secondPerson.Identity: " + personsHaveIdenticalIdentities);

        Console.WriteLine("firstPerson.Identity: " + firstPerson.Identity + System.Environment.NewLine + "secondPerson.Identity: " + secondPerson.Identity );

​

        personsHaveIdenticalIdentities = firstPerson.ArePersonEqual(thirdPerson);

        Console.WriteLine("firstPerson.Identity == thirdPerson.Identity: " + personsHaveIdenticalIdentities);

        Console.WriteLine("firstPerson.Identity: " + firstPerson.Identity + System.Environment.NewLine + "thirdPerson.Identity: " + thirdPerson.Identity );

​

        personsHaveIdenticalIdentities = secondPerson.ArePersonEqual(fourthPerson);

        Console.WriteLine("secondPerson.Identity == fourthPerson.Identity: " + personsHaveIdenticalIdentities);

        Console.WriteLine("secondPerson.Identity: " + secondPerson.Identity + System.Environment.NewLine + "fourthPerson.Identity: " + fourthPerson.Identity );

}

​

    public class Person

    {

        public Person(string firstname, string lastname, Guid identity = new Guid())

        {

            Identity = identity;

            FirstName = firstname;

            LastName = lastname;

        }

​

        public Guid Identity { get; internal set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

​

        public bool ArePersonEqual(Person person)

        {

            return Identity == person.Identity;

        }

    }

}

​

​