public class Person

{

    public string Name { get; set; }

    public int Age { get; set; }

    public Person(string name, int age)

    {

        Name = name;

        Age = age;

    }

}

​

class Program

{

    private Person globalP;

    static void Main()

    {

        this.globalP = new Person("Jonathan", 69);

        this.globalP = this.calculatePerson(this.globalP);

        Person constantVariable = new Person("Leopold", 6);

        constantVariable = this.calculatePerson(constantVariable);

    }

    public Person calculatePerson(Person x)

    {

        x.Age++;

        x.Name = "Old " + x.Name;

        return Person;

    }

}