/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/
/*
  Example7_2.cs illustrates polymorphism
*/

using System;


// declare the MotorVehicle class
class MotorVehicle
{

  // declare the fields
  public string make;
  public string model;

  // define a constructor
  public MotorVehicle(string make, string model)
  {
    this.make = make;
    this.model = model;
  }

  // define the Accelerate() method (may be overridden in a
  // derived class)
  public virtual void Accelerate()
  {
    Console.WriteLine(model + " accelerating");
  }

}


// declare the Car class (derived from MotorVehicle)
class Car : MotorVehicle
{

  // define a constructor
  public Car(string make, string model) :
  base(make, model)
  {
    // do nothing
  }

  // override the base class Accelerate() method
  public override void Accelerate()
  {
    Console.WriteLine("Pushing gas pedal of " + model);
    base.Accelerate();  // calls the Accelerate() method in the base class
  }

}


// declare the Motorcycle class (derived from MotorVehicle)
class Motorcycle : MotorVehicle
{

  // define a constructor
  public Motorcycle(string make, string model) :
  base(make, model)
  {
    // do nothing
  }

  // override the base class Accelerate() method
  public override void Accelerate()
  {
    Console.WriteLine("Twisting throttle of " + model);
    base.Accelerate();  // calls the Accelerate() method in the base class
  }

}


public class Example7_2
{

  public static void Main()
  {

    // create a Car object and call the object's Accelerate() method
    Car myCar = new Car("Toyota", "MR2");
    myCar.Accelerate();

    // create a Motorcycle object and call the object's Accelerate() method
    Motorcycle myMotorcycle = new Motorcycle("Harley-Davidson", "V-Rod");
    myMotorcycle.Accelerate();

  }

}


           
          

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/


/* When a virtual method is not overridden, 
   the base class method is used. */ 
 
using System; 
 
class Base { 
  // Create virtual method in the base class.  
  public virtual void who() { 
    Console.WriteLine("who() in Base"); 
  } 
} 
 
class Derived1 : Base { 
  // Override who() in a derived class. 
  public override void who() { 
    Console.WriteLine("who() in Derived1"); 
  } 
} 
 
class Derived2 : Base { 
  // This class does not override who(). 
} 
 
public class NoOverrideDemo { 
  public static void Main() { 
    Base baseOb = new Base(); 
    Derived1 dOb1 = new Derived1(); 
    Derived2 dOb2 = new Derived2(); 
 
    Base baseRef; // a base-class reference 
 
    baseRef = baseOb;  
    baseRef.who(); 
 
    baseRef = dOb1;  
    baseRef.who(); 
 
    baseRef = dOb2;  
    baseRef.who(); // calls Base's who() 
  } 
}


           
          

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/


// Demonstrate a virtual method. 
 
using System; 
 
class Base { 
  // Create virtual method in the base class.  
  public virtual void who() { 
    Console.WriteLine("who() in Base"); 
  } 
} 
 
class Derived1 : Base { 
  // Override who() in a derived class. 
  public override void who() { 
    Console.WriteLine("who() in Derived1"); 
  } 
} 
 
class Derived2 : Base { 
  // Override who() again in another derived class. 
  public override void who() { 
    Console.WriteLine("who() in Derived2"); 
  } 
} 
 
public class OverrideDemo { 
  public static void Main() { 
    Base baseOb = new Base(); 
    Derived1 dOb1 = new Derived1(); 
    Derived2 dOb2 = new Derived2(); 
 
    Base baseRef; // a base-class reference 
 
    baseRef = baseOb;  
    baseRef.who(); 
 
    baseRef = dOb1;  
    baseRef.who(); 
 
    baseRef = dOb2;  
    baseRef.who(); 
  } 
}


           
          

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Use virtual methods and polymorphism.

using System;

class TwoDShape {
double pri_width; // private
double pri_height; // private
string pri_name; // private

// A default constructor.
public TwoDShape() {
width = height = 0.0;
name = “null”;
}

// Parameterized constructor.
public TwoDShape(double w, double h, string n) {
width = w;
height = h;
name = n;
}

// Construct object with equal width and height.
public TwoDShape(double x, string n) {
width = height = x;
name = n;
}

// Construct an object from an object.
public TwoDShape(TwoDShape ob) {
width = ob.width;
height = ob.height;
name = ob.name;
}

// Properties for width, height, and name
public double width {
get { return pri_width; }
set { pri_width = value; }
}

public double height {
get { return pri_height; }
set { pri_height = value; }
}

public string name {
get { return pri_name; }
set { pri_name = value; }
}

public void showDim() {
Console.WriteLine(“Width and height are ” +
width + ” and ” + height);
}

public virtual double area() {
Console.WriteLine(“area() must be overridden”);
return 0.0;
}
}

// A derived class of TwoDShape for triangles.
class Triangle : TwoDShape {
string style; // private

// A default constructor.
public Triangle() {
style = “null”;
}

// Constructor for Triangle.
public Triangle(string s, double w, double h) :
base(w, h, “triangle”) {
style = s;
}

// Construct an isosceles triangle.
public Triangle(double x) : base(x, “triangle”) {
style = “isosceles”;
}

// Construct an object from an object.
public Triangle(Triangle ob) : base(ob) {
style = ob.style;
}

// Override area() for Triangle.
public override double area() {
return width * height / 2;
}

// Display a triangle's style.
public void showStyle() {
Console.WriteLine(“Triangle is ” + style);
}
}

// A derived class of TwoDShape for rectangles.
class Rectangle : TwoDShape {
// Constructor for Rectangle.
public Rectangle(double w, double h) :
base(w, h, “rectangle”){ }

// Construct a square.
public Rectangle(double x) :
base(x, “rectangle”) { }

// Construct an object from an object.
public Rectangle(Rectangle ob) : base(ob) { }

// Return true if the rectangle is square.
public bool isSquare() {
if(width == height) return true;
return false;
}

// Override area() for Rectangle.
public override double area() {
return width * height;
}
}

public class DynShapes {
public static void Main() {
TwoDShape[] shapes = new TwoDShape[5];

shapes[0] = new Triangle(“right”, 8.0, 12.0);
shapes[1] = new Rectangle(10);
shapes[2] = new Rectangle(10, 4);
shapes[3] = new Triangle(7.0);
shapes[4] = new TwoDShape(10, 20, “generic”);

for(int i=0; i < shapes.Length; i++) { Console.WriteLine("object is " + shapes[i].name); Console.WriteLine("Area is " + shapes[i].area()); Console.WriteLine(); } } } [/csharp]

   

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 */
using System;

namespace Client.Chapter_5___Building_Your_Own_Classes
{
  public class MyMainClass13
  {
    static void Main(string[] args)
    {
      //The function called is based
      //upon the type called by new.
      B MyB = new C();

      MyB.Display();    //Calls C's Display
    }
  }
  abstract class A
  {
    public abstract void Display();
  }
  class B: A
  {
    public override void Display()
    {
      Console.WriteLine("Class B's Display Method");
    }
  }
  class C: B
  {
    public override void Display()
    {
      Console.WriteLine("Class C's Display Method");
    }
  }
  class D: C
  {
    public override void Display()
    {
      Console.WriteLine("Class D's Display Method");
    }
  }

}

           
          

   

/*
 * C# Programmers Pocket Consultant
 * Author: Gregory S. MacBeth
 * Email: gmacbeth@comporium.net
 * Create Date: June 27, 2003
 * Last Modified Date:
 */
using System;

namespace Client.Chapter_5___Building_Your_Own_Classes
{
  public class MyMainClass12 {
    static void Main(string[] args)
    {
      //The function called is based
      //upon the type called by new.
      B MyB = new C();
      D MyD = new D();

      MyB.Display();    //Calls C Display
      MyD.Display();    //Calls D Display
    }
  }
  public interface A
  {
    void Display();
  }
  class B: A
  {
    public virtual void Display()
    {
      Console.WriteLine("Class B's Display Method");
    }
  }
  class C: B
  {
    public override void Display()
    {
      Console.WriteLine("Class C's Display Method");
    }
  }
  class D: C
  {
    public override void Display()
    {
      Console.WriteLine("Class D's Display Method");
    }
  }

}

           
          

   
 

using System;

public class Class1 {
    public static void Main(string[] strings) {
        BankAccount ba = new BankAccount();
        Test1(ba);

        SavingsAccount sa = new SavingsAccount();
        Test1(sa);
        Test2(sa);

        SpecialSaleAccount ssa = new SpecialSaleAccount();
        Test1(ssa);
        Test2(ssa);
        Test3(ssa);

        SaleSpecialCustomer ssc = new SaleSpecialCustomer();
        Test1(ssc);
        Test2(ssc);
        Test3(ssc);
        Test4(ssc);
    }

    public static void Test1(BankAccount account) {
        Console.Write("to Test(BankAccount)");
        account.Withdrawal(100);
    }

    public static void Test2(SavingsAccount account) {
        Console.Write("to Test(SavingsAccount)");
        account.Withdrawal(100);
    }

    public static void Test3(SpecialSaleAccount account) {
        Console.Write("to Test(SpecialSaleAccount)");
        account.Withdrawal(100);
    }

    public static void Test4(SaleSpecialCustomer account) {
        Console.Write("to Test(SaleSpecialCustomer)");
        account.Withdrawal(100);
    }
}

public class BankAccount {
    virtual public void Withdrawal(double dWithdrawal) {
        Console.WriteLine(" invokes BankAccount.Withdrawal()");
    }
}

public class SavingsAccount : BankAccount {
    override public void Withdrawal(double dWithdrawal) {
        Console.WriteLine(" invokes SavingsAccount.Withdrawal()");
    }
}
public class SpecialSaleAccount : SavingsAccount {
    new virtual public void Withdrawal(double dWithdrawal) {
        Console.WriteLine(" invokes SpecialSaleAccount.Withdrawal()");
    }
}

public class SaleSpecialCustomer : SpecialSaleAccount {
    override public void Withdrawal(double dWithdrawal) {
        Console.WriteLine
          (" invokes SaleSpecialCustomer.Withdrawal()");
    }
}