simple notes Unit 4-Inheritance (2).pptx

c++

1. UNIT 4 INHERITANCE

2. Syllabus Inheritance- Defining derived classes-Visibility modes- Single , Multilevel, Multiple, Hierarchical and Hybrid inheritance Virtual base classes Abstract classes Constructors in derived classes- Nesting of classes.

3. What? Inheritance is the capability of one class to acquire properties and characteristics from another class. The class whose properties are inherited by other class is called the   Parent  or  Base  or  Super  class. And , the class which inherits properties of other class is called  Child  or  Derived  or  Sub  class.

4. Example

5. Adv : Reusability of code

6. Syntax c lass derivedclassname : visibility label baseclassname { }; Animal dog Eg : class dog : public Animal { }; Keyword p rivate/public/protected

7. Types C++ offers five types of Inheritance. They are: Single Inheritance Multiple Inheritance Hierarchical Inheritance Multilevel Inheritance Hybrid Inheritance (also known as Virtual Inheritance)

8. Single Inheritance

9. Multiple Inheritance

10. Multilevel Inheritance

11. Heirarchical Inheritance

12. Hybrid Inheritance

13. Visibility labels/modes – private/public Base class - demo private – a,b public- read() Derived class – demochild private – c,d public –display() Private Inheritance All public members of base class b ecome private in derived Public Inheritance All public members of base class b ecome public in derived Note:- Private members of base class not inherited – Data Hiding After Inheritance - Derived Class private – c,d,read () public –display() After Inheritance - Derived Class private – c,d public –read(), display()

14. Try to do- Example 1 c lass B p rivate a Public b g et_ab () g et_a () s how_a () class D p rivate c public m ul () d isplay()

15. Example 2 c lass B p rivate a Public b g et_ab () g et_a () s how_a () class D p rivate C public m ul () d isplay()

16. Making Private Member Inheritable If private data of base class need to be inherited Modifying private as public Problem:???? Data hiding violated So 3 rd visibility label – protected Limited purpose Can be accessed by base class and immediate derived class

17. Visibility labels/modes – private/public/protected Base class - demo private – a,b protected- c public- read() Derived class – demochild private – d,e protected- f public –display() Private Inheritance All public & protected members of base class b ecome private in derived Protected Inheritance All protected &public members of base class b ecome protected in derived Note:- Private members of base class not inherited – Data Hiding After Inheritance - Derived Class private – d,e,c,read () Protected - f public –display() After Inheritance - Derived Class private – d,e p rotected – f, c,read () public –display()

18. Base class - demo private – a,b protected- c public- read() Derived class – demochild private – d,e protected- f public –display() Public Inheritance All protected members of base class b ecome protected and public members become p ublic in derived After Inheritance - Derived Class private – d,e p rotected – f, c public –read(), display() Note:- Private members of base class not inherited – Data Hiding

19. Visibility Labels

20. Inheritance Visibility Mode

21. Single class A { }; c lass B:public A { }; Multiple Class A { }; Class B { }; Class c:public A,public B { }; Multilevel c lass A { }; c lass B:public A { }; c lass C:public B { }; Hierarchical Class A { }; Class B :public A { }; Class C:public A { }; Class D: public A { }; Hybrid Class A { }; Class B:public A { }; Class c:public A { }; Class D: public B ,public C { {;

22. Ambiguity Resolution in Inheritance Output Class

23. Virtual Base Class Hybrid Inheritance, Here all protected and public members of Grandparent class is inherited twice via Parent 1 and Parent 2 c lass to Child Class Ambiguity arises Can be avoided by making common base class as virtual base class

24. Example

25. Abstract Class Class that is not used to create objects Created to act as base class

26. Program Explanation Inheritance Programs

27. Constructors in Derived Class If any base class constructor take argmnt then there should be derived constructor Execution order Multiple Inheritance – order in declaration of derived class Multilevel Inheritance- order of Inheritance

28. General Form Derivedclassconstructor (arg1,arg2,… argn ): Base 1(arg1), Base 2(arg2) ……………. ……………. Base n( argn ) { } Eg : D( int a,int b, int c, int d): A ( inta , int b), B( int c) { d1=d; }

29. Example Program Output

30. Nesting

31. THANK YOU