This document discusses inheritance in object-oriented programming. It defines inheritance as allowing code reuse through classes inheriting traits from parent classes. The document covers different types of inheritance like single, multi-level, multiple and hierarchical inheritance. It also discusses inheritance in various programming languages like C++, Java, Python and ADA. The advantages of inheritance are code reuse and extending parent classes without modifying them, while disadvantages include subclasses being brittle and inheritance relationships not changing at runtime.

1. Sharda University
Department Of Computer Science And Engineering
School Of Engineering And Technology
Greater Noida, U. P.

2. Presented By
Hirra Sultan
CSE-B 2nd year
Roll No. 120101091
Enrollment No. 2012017740
Supervisor: Mr. A. K. Sahoo
prlhirr@gmail.com

3. Introduction
Background
 The first OOP language designed for the
first personal computer was smalltalk.
 When OOP was integrated into C
language, the resulting language was
called C++ and it became the first object-
oriented language to be widely used
commercially.
 Later java and other OOP languages were
developed.

4. Concept of Inheritance
 Inheritance is that feature of an OOP language
which allows reusability of code of a class and
is considered corner stone of OOP languages.
 Using inheritance, we can create a general
class that defines traits common to a set of
related items.
 This class may then be inherited by other,
more specific classes, each adding only those
things that are unique to the inheriting class.

5.  Base class: The class which gets inherited is
called a base class. The code of this class is
passed on to subclasses where it is reused.
 Derived class: A subclass is a derived class
which inherits the base class and uses its
member functions.
 Un-inheritable class: A class may be
declared as un-inheritable by adding certain class
modifiers to the class declaration before the
"class" keyword and the class identifier
declaration. Such sealed classes
restrict reusability.
Definitions

6. Types of Inheritance
 Single Inheritance: In single
inheritance there is only one super class
and only one sub class.
 Multi-level inheritance: In multi-level
inheritance a derived class is inherited by
another class thus making multiple levels.

7.  Multiple Inheritance: A class can inherit
the attributes of two or more classes. This
is known as multiple inheritance.
 Hierarchical inheritance: When a base
class is inherited by multiple derived
classes it is called hierarchical inheritance.
 Hybrid inheritance: This is a mixture of
two or more inheritances in a single code.

8. Inheritance may be derived in three forms
which decides the way inherited data
members can be used.
 Public Inheritance: Public members of
the base class become public members of
the derived class and protected members
of the base class
become protected members of the derived
class.

9.  Protected Inheritance: When
deriving from a protected base class, public
and protected members of the base class
become protected members of the derived
class.
 Private Inheritance: When deriving
from a private base class, public and
protected members of the base class
become private members of the derived
class.

10. Inheritance in C++
 In C++ all the five types of inheritances are
applicable.
 Friend functions and constructors can’t be
inherited.
 The general syntax of inheritance is:
class derived-class-name : visibility-mode base-
class-name
{
…// members of derived class
};

11. Inheritance in Java
 The general syntax of inheritance is:
Class Subclass-name extends superclass-
name
{
//methods and fields
}

12.  The keyword extends indicates that we are
making a new class that derives from an
existing class.
 Multiple and hybrid inheritance is not
supported. This reduces the program
complexity.
 Constructors are not inherited by a subclass.

13. Inheritance in Python
 Instances inherit from classes, and classes
inherit from super classes.
 Python supports a limited form of multiple
inheritance.
 The syntax for inheritance in python is:
class DerivedClassname
(BaseClassName):
<statement-1>
.
<statement-N>

14. Inheritance in ADA
 In Ada 95 terminology, types that can have
parents or children are termed “tagged
types”, and have the keyword “tagged” as
part of their definition.
 If we don't redefine a subprogram for a
given type, the closest ancestor's defined
subprogram will be used.

15. Advantages
 We save time because much of the code
needed for our class is already written.
 We can extend and revise a parent class
without corrupting the existing parent class
features.

16. Disadvantages
 Removing or swapping out a superclass
will usually break subclasses.
 It's inflexible.
 Inheritance relationships generally can't
be altered at runtime.