INHERITANCE Introduction Types Syntax Visibility Modes Example Programs

INHERITANCE Introduction Types Syntax Visibility Modes Example Programs 1

What Is Inheritance? Provides a way to create a new class from an existing class The new class is a specialized version of the existing class Ex: ◦ ANIMAL DOG Poodle The relationship is “is-a” DOG is a ANIMAL with additional features 2

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The "is a" Relationship • Inheritance establishes an "is a" relationship between classes. – Student { id, name, dept, avg } – CSE_Student {rank} – Placement ( placed } Terminologies Base Class – Inherited Derived Class – Inherits from base class An object of a derived class 'is a(n)' object of the base class A derived object has all of the characteristics of the base class 5

TYPES In C++, we have 5 different types of Inheritance. Namely, ◦ Single Inheritance ◦ Multiple Inheritance ◦ Hierarchical Inheritance ◦ Multilevel Inheritance ◦ Hybrid Inheritance 6

Merits Reusability Application Development Time is Less Application Execution time is Less Memory Redundancy of the code is reduced 7

Types of Inheritance 1. Single class Inheritance: Single inheritance is the one where you have a single base class and a single derived class. Class Employee Class Manager It is a Base class (super) it is a sub class (derived)

Types of Inheritance 2. Multilevel Inheritance: In Multi level inheritance, a class inherits properties from another derived class. Class A it is a Base class (super) of B Class B it is a sub class (derived) of A and base class of class C Class C derived class(sub) of class B

Types of Inheritance 3. Multiple Inheritances: In Multiple inheritances, a derived class inherits from multiple base classes. It has properties of both the base classes. Class A Class C Class B Derived class Base class

Types of Inheritance 4. Hierarchical Inheritance: In hierarchical Inheritance, it's like an inverted tree. So multiple classes inherit from a single base class. It's quite analogous to the File system in a unix based system. Class A Class B Class D Class C

Types of Inheritance 5. Hybrid Inheritance: üIn this type of inheritance, we can have mixture of number of inheritances but this can generate an error of using same name function from no of classes, which will bother the compiler to how to use the functions. üTherefore, it will generate errors in the program. This has known as ambiguity or duplicity. üAmbiguity problem can be solved by using virtual base classes

Types of Inheritance 5. Hybrid Inheritance: Class A Class B Class C Class D

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