Inheritance in C++

Inheritance in C++

The process of obtaining the data members and methods from one class to another class is known as inheritance. It is one of the fundamental features of object-oriented programming.

Important points

• In the inheritance the class which is give data members and methods is known as base or super or parent class.
• The class which is taking the data members and methods is known as sub or derived or child class.

class subclass_name : superclass_name  
{  
    // data members
   // methods  
}  

Real Life Example of Inheritance in C++

The real life example of inheritance is child and parents, all the properties of father are inherited by his son.

Diagram

In the above diagram data members and methods are represented in broken line are inherited from faculty class and they are visible in student class logically.

Advantage of inheritance

If we develop any application using this concept than that application have following advantages,

• Application development time is less.
• Application take less memory.
• Application execution time is less.
• Application performance is enhance (improved).
• Redundancy (repetition) of the code is reduced or minimized so that we get consistence results and less storage cost.

Tpyes of Inheritance

Based on number of ways inheriting the feature of base class into derived class it have five types they are:

• Single inheritance
• Multiple inheritance
• Hierarchical inheritance
• Multiple inheritance
• Hybrid inheritance

Single inheritance

In single inheritance there exists single base class and single derived class.

Multiple inheritances

In multiple inheritances there exists single base class, single derived class and multiple intermediate base classes.

Single base class + single derived class + multiple intermediate base classes.

Intermediate base classes

An intermediate base class is one in one context with access derived class and in another context same class access base class.

Hence all the above three inheritance types are supported by both classes and interfaces.

Multiple inheritance

In multiple inheritance there exist multiple classes and singel derived class.

Hybrid inheritance

Combination of any inheritance type

Inheriting the feature from base class to derived class

In order to inherit the feature of base class into derived class we use the following syntax

class classname-2 : classname-1
{
variable  declaration;
method declaration;
}

Explanation

• classname-1 and classname-2 represents name of the base and derived classes respectively.
• : is operator which is used for inheriting the features of base class into derived class it improves the functionality of derived class.

#include<iostream.h>
#include<conio.h>

class employee
{
public:
int salary;
};
class developer : public employee
{
employee e;
public:
void salary()
{
cout<<"Enter employee salary: ";
cin>>e.salary;   // access base class data member
cout<<"Employee salary: "<<e.salary;
}
};

void main()
{
clrscr();
developer obj;
obj.salary();
getch();
}

Enter employee salary: 50000
Employee salary: 50000