2. Outline
• Introduction
• Protected members in inheritance
• Relationship between Base Classes and Derived Classes
• Benefits and Drawbacks of Inheritance
• Constructors and Destructors in Derived Classes
• Public, Protected and Private Inheritance
• Software Engineering with Inheritance
3. Introduction
• Inheritance is a core concept in object-oriented programming (OOP).
It allows a class to inherit properties and behaviors from another
class. This is a powerful way to reuse code and promote code
abstraction.
• Inheritance works by creating a subclass that inherits from a
superclass. The subclass inherits all of the attributes and methods of
the superclass, and it can also add its own attributes and methods.
• Parent – Child Relationship.
4. Types of inheritance
Here are some of the types of inheritance:
• Single inheritance: A subclass inherits from a single superclass.
• Multiple inheritance: A subclass inherits from multiple superclasses.
• Hierarchical inheritance: A class hierarchy is formed when a subclass
inherits from another subclass.
• Hybrid inheritance: A mix of two or more of the above types of
inheritance occurs.
5. Syntax
class Subclass’Name : access_specifier BaseClass’Name {
// members of subclass
};
The access_specifier can be one of the following:
• public: The subclass inherits all of the public members of the base
class.
• protected: The subclass inherits all of the protected members of the
base class.
• private: The subclass inherits none of the members of the base class.
7. Protected members in inheritance,oop,c++
In C++, protected members are members of a class that can only be
accessed by the class itself, its subclasses, and friends.
• Protected members are similar to private members, but they can be
inherited by subclasses. Private members are not accessible to
subclasses or friends.
• The syntax for declaring a protected member in C++ is:
class MyClass {
protected:
int x;
};
8. Relationship between Base Classes and
Derived Classes
In C++, a base class is a class from which other classes are derived. The
derived classes are called subclasses. The base class is the "parent" of the
subclasses, and the subclasses are the "children" of the base class.
The relationship between a base class and its subclasses is one of
inheritance. This means that the subclasses inherit all of the properties and
behaviors of the base class. The subclasses can then add their own properties and
behaviors, or they can override the properties and behaviors of the base class.
9. Benefits and Drawbacks of Inheritance
Here are some of the benefits of using inheritance in C++:
I. It allows us to reuse code.
II. It helps us to organize our code.
III. It can help us to make our code more robust and easier to
maintain.
Here are some of the drawbacks of using inheritance in C++:
I. It can make the code more complex.
II. It can make it difficult to track down the source of errors.
10. Constructors and Destructors in Derived Classes
When a subclass inherits from a base class, the subclass inherits the base class's constructors and
destructors. However, the subclass can also define its own constructors and destructors.
If the subclass defines its own constructors, the base class's constructors will be called
automatically when the subclass object is created.
The order in which the constructors are called is as follows:
• The base class's default constructor is called.
• The subclass's default constructor is called.
• If the subclass defines any parameterized constructors, they are called in the order that they are
defined.
If the subclass defines its own destructor, the base class's destructor will be called automatically
when the subclass object is destroyed. The order in which the destructors are called is as follows:
• The subclass's destructor is called.
• The base class's destructor is called.
11. Example
When a DerivedClass object is created,
the following happens:
• The BaseClass class's default constructor
is called.
• The DerivedClass class's default
constructor is
called.
When a DerivedClass object is destroyed,
the following happens:
• The DerivedClass class's destructor is
called.
• The BaseClass class's destructor is
called.
12. Public, Protected and Private Inheritance
• Public inheritance is the default type of inheritance in C++. When a class
inherits from another class in public mode, the subclass inherits all of the
public members of the base class. This means that the subclass can access
the public members of the base class as if they were its own members.
• Protected inheritance is a type of inheritance where the subclass inherits
all of the protected members of the base class. This means that the
subclass can access the protected members of the base class, but it cannot
access the public members of the base class.
• Private inheritance is a type of inheritance where the subclass inherits all
of the private members of the base class. This means that the subclass can
only access the private members of the base class through the base class's
methods.
13. Public, Protected and Private Inheritance…..
Type of inheritance Access to base class members
Public inheritance Public and protected members
Protected inheritance Protected members
Private inheritance Private members
14. Software Engineering with Inheritance
• Inheritance is a powerful tool in software engineering that can be used to
improve the design and implementation of our code. It allows us to reuse code
that has already been written, and it can also help us to abstract away the details
of how something works.
Here are some of the ways that inheritance can be used in software engineering:
• To create a hierarchy of classes: Inheritance can be used to create a hierarchy of
classes, where each class inherits from a more general class. This can help to
organize our code and make it easier to understand.
• To implement polymorphism: Inheritance can be used to implement
polymorphism, which allows us to treat different objects in the same way. This
can make our code more flexible and easier to use.
• To reuse code: Inheritance can be used to reuse code that has already been
written. This can save us time and effort, and it can also help to keep our code
consistent.
