---

Polymorphism

Polymorphism is a fundamental concept in object-oriented programming (OOP) that allows objects of different classes to respond to the same method call in different ways. It enables dynamic behavior and code flexibility, making programs more adaptable to different situations.

The Polymorphism Principle

Polymorphism stems from the Greek word "poly", meaning "many", and "morph", meaning "form". It refers to the ability of objects to take on many forms and respond to the same method call in different ways, based on their type or implementation.

Types of Polymorphism

• Method Overloading: Allows a class to have multiple methods with the same name but different parameters. This enables the creation of methods that perform similar operations but handle different data types or argument sets.
• Method Overriding: Allows a derived class to override a method from its base class, providing a specialized implementation for that method. This enables the creation of classes that adapt existing behavior to their specific needs.
• Operator Overloading: Allows custom behavior for operators, such as addition, subtraction, or comparison, based on the data types involved. This enables the creation of operators that work consistently with different data types.

Example: Shape Class Hierarchy

Consider a Shape class representing a generic shape:

class Shape {

  // Abstract method

  public abstract double GetArea();

}

 

Create derived classes Circle and Rectangle that inherit from the Shape class:

class

 Circle : Shape {

  private

 double radius;

 

  public

 Circle(double radius) {

    this.radius = radius;

  }

 

  public

 override

 double

 GetArea() {

    return Math.PI * radius * radius;

  }

}

 

class

 Rectangle : Shape {

  private

 double width;

  private

 double height;

 

  public

 Rectangle(double width, double height) {

    this.width = width;

    this.height = height;

  }

 

  public

 override

 double

 GetArea() {

    return width * height;

  }

}

 

Polymorphism in Action

Create an array of different Shape objects:

Shape[] shapes = new Shape[] { new Circle(5), new Rectangle(3, 4) };

 

Calculate the area of each shape using the GetArea() method:

foreach (Shape shape in shapes) {

  double area = shape.GetArea();

  Console.WriteLine("Area of " + shape.GetType().Name + ": " + area);

}

 

This code will print the area of each shape based on its specific implementation of the GetArea() method, demonstrating polymorphism.

Polymorphism Benefits

• Dynamic Behavior: Polymorphism allows programs to adapt their behavior to different situations based on the type of objects involved, making them more flexible and responsive.
• Code Reusability: Polymorphism enables the creation of methods with generic names that can be used with different data types, promoting code reusability.
• Code Maintainability: Polymorphism makes code easier to maintain by allowing changes in method implementations without affecting how the method is called, reducing the need for code modifications throughout the program.

Conclusion

Polymorphism is a powerful feature of C# programming that enables dynamic behavior, code reusability, and code maintainability. It plays a crucial role in OOP principles, allowing programmers to create flexible and adaptable programs that can handle different data types and situations effectively. Understanding polymorphism is essential for developing high-quality C# applications.