namespace Txst2_1
{
class Animal
{
private Boolean m_sex;
private int m_age;
public bool Sex
{
get { return m_sex; }
set { m_sex = false; }
}
public int Age
{
get { return m_age; }
set { m_age = value; }
}
public virtual string Introduce()
{
if (Sex == true)
return "This is a male Animal";
else
return "This is a female Animal";
}
}
class Dog:Animal
{
public Dog()
{
Sex = true;
}
public override string Introduce()
{
if (Sex == true)
return "This is a male Dog";
else
return "This is a female Dog";
}
}
class Cat:Animal
{
public override string Introduce()
{
if (Sex == true)
return "This is a male Cat";
else
return "This is a female Cat";
}
}
class Program
{
static void Main(string[] args)
{
Animal ani = new Animal();
Console.WriteLine(ani.Introduce());
Animal dog = new Dog();
Console.WriteLine(dog.Introduce());
Animal cat = new Cat();
Console.WriteLine(cat.Introduce());
Console.Read();
}
}
}

namespace Txst_2._1 { class Animal { private Boolean m_sex; private string m_sound; public Animal() { m_sex = false; m_sound = "Howl..."; } public bool Sex { get{ return m_sex; } set { m_sex = value; }

} public string Sound { get { return m_sound; } set { m_sound = value; } } public virtual string Roar() { return "Animal" + m_sound; } } class Dog:Animal { public Dog() { Sex = true; Sound = "Wow..."; } public override string Roar() { return "Dog:" + Sound; } } class Cat:Animal { public Cat() { Sound = "Miaow..."; } public override string Roar() { return "Cat:" + Sound; } } class Cow:Animal { public Cow() { Sound = "Moo..."; } public override string Roar() { return "Cow:" + Sound; } } class Program { static void Main(string[] args) {

Animal animal; animal = new Dog(); Console.WriteLine(animal.Roar()); animal = new Cat(); Console.WriteLine(animal.Roar()); animal = new Cow(); Console.WriteLine(animal.Roar()); Console.Read(); } } }

2.1-11