Static Classes

• Objects cannot be created from a static class.

• A static class may only contain static members and methods.

• These are highly useful as classes that contain utility methods.

public class Program
{
    static void Main(string[] args)
    {
        var person = new Person() { Name = "Sach", DOB = new DateTime(1981, 5, 21) };
        Utility.PrintDetails(person.Name, Utility.GetAge(person.DOB));

        var pet = new Pet() { Name = "Kitty", DOB = new DateTime(1990, 3, 21) };
        Utility.PrintDetails(pet.Name, Utility.GetAge(pet.DOB));
    }
}

public class Person
{
    public string Name { get; set; }
    public int Phone { get; set; }
    public DateTime DOB { get; set; }

}

public class Pet
{
    public string Name { get; set; }
    public DateTime DOB { get; set; }
}

public static class Utility
{
    public static string GetAge(DateTime dob)
    {
        var age = DateTime.Today.Year - dob.Year;
        return string.Format("{0} years", age);
    }

    public static void PrintDetails(string name, string age)
    {
        Console.WriteLine("Name: {0}, {1}", name, age);
    }
}