Polymorphism (2)
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This document discusses polymorphism in C# through method overloading and overriding. It shows how to create a base DrawingObject class that can be inherited by Line, Circle, and Square classes, where each subclass overrides the Draw method to output its type. The Main method creates instances of each subclass and calls their Draw methods to demonstrate polymorphism. The document also compares abstract classes and interfaces, noting that abstract classes can contain implemented methods while interfaces only contain signatures, and interfaces allow multiple inheritance while abstract classes do not.
Polymorphism (2)
- 1. We Can Implement Polymorphism In C # Through Method Overloading and Method Overriding POLYMORPHISM 12/7/2015 1
- 2. Method Overloading & Method Overriding Public class Drawing Object { public void Draw() { Console .Write Line(“ I’m just a generic drawing object.”); } } POLYMORPHISM Shows the drawing object class this will be the base class for other objects to inherit from ,It has a single method named Draw() .the Draw Method has a virtual Modifier .This virtual Modifier indicates to derived classes that they can override this method 12/7/2015 2
- 3. Public class Line: Drawing Object { public override void Draw() { Console .Write Line(“ I’m a Line.”); } } Public class Circle : Drawing Object { public override void Draw() { Console .Write Line (“ I’m a Circle .”); METHODOVERLOADING& METHODOVERRIDING 12/7/2015 3
- 4. Public class Square : Drawing Object { public override void Draw() { Console .Write Line(“ I’m a Square.”); } } Method Overloading & Method Overriding 12/7/2015 4
- 5. Class Main { Public static void main() { Drawing ObjdObj=newDrawingObj(); dObj.Draw(); DrawingObject li=new Line(); Li.Draw(); DrawingObject cr=new Circle(); Cr.Draw(); DrawingObject sq=newSquare(); Sq.Draw(); Console.ReadKey(); } } } Method Overloading & Method Overriding 12/7/2015 5
- 6. An abstract class can implement methods An abstract class can contain fields An abstract class can contain constructors or destructors An interface cannot implement methods An interface can inherit from another class An interface can contain signature ABSTRACT CLASS & INTERFACE 12/7/2015 6
- 7. An abstract class cannot be inherited from by a class . Abstract class cannot support multiple inheritances Interface cannot contain constructors or destructors Interface can support multiple inheritances ABSTRACT CLASS & INTERFACE 12/7/2015 7
- 8. An interface look like a class but has no implementation.The only things that they contain are only signature of methods events and or properties .the reason interface only provide declarations is because they are inherit by classes and which provide implementation for each interface member declared INTERFACE 12/7/2015 8
- 9. An Abstract class has no implementation like interface . Implementation of methods can be use by the child class ABSTRACT CLASS 12/7/2015 9