Inheritance

Inheritance 23-01-2016

Inheritance Inheritance is the capability of one class to acquire properties and characteristics from another class. For using Inheritance concept in our program we must use at least two classes. 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.

Syntax: Class subclass : < access specifier (public, protected, private) > Superclass. class Person {........ class MathsTeacher : public Person {........

Access specifiers in Inheritance If access specifier is Public i.e., Class subclass: public Superclass Then the protected member of super class becomes protected members of sub class and public becomes public

Access specifiers in Inheritance (Continuation) If access specifier is protected i.e., Class subclass: protected Superclass Then the protected and public members of super class becomes protected members of sub class.

Access specifiers in Inheritance (Continuation) If access specifier is private i.e., Class subclass: private Superclass Then the protected and public members of super class becomes private members of sub class.

Simple Inheritance program: #include <iostream> using namespace std; // Base class class Shape { protected: int width; int height; public: void setwidth(int w) { width = w; void setheight(int h) { height = h; class Rectangle: public Shape { public: int getarea() { return (width * height); int main(void) { Rectangle Rect; Rect.setWidth(2); Rect.setHeight(2); cout << "Total area: " << Rect.getArea() << endl; return 0;

Advantages of Inheritance Inheritance makes the code reusable. When we inherit an existing class, all its methods and fields become available in the new class, hence code is reused. Fast implementation time

Types of Inheritance: In C++, we have 5 different types of Inheritance. Namely, 1. Single Inheritance 2. Multiple Inheritance 3. Hierarchical Inheritance 4. Multilevel Inheritance 5. Hybrid Inheritance (also known as Virtual Inheritance)

Single Inheritance Single Inheritance: In this type of inheritance one derived class inherits from only one base class. It is the simplest form of Inheritance. Syntax: class derived-class: access-specifier Base-class Class B: public A{

Multiple Inheritance: Multiple Inheritance: In this type of inheritance a single derived class may inherit from two or more than two base classes. Syntax: class derived-class: access-specifier basea, access-specifier baseb... Class c: public A, public B{

Example for Multiple Inheritance: #include <iostream> using namespace std; class Shape { protected: int width; int height; public: void setwidth(int w) { width = w; void setheight(int h) { height = h; class Rectangle: public Shape, public PaintCost { public: int getarea() { return (width * height); int main(void) { Rectangle Rect; int area; int w,h; cout<<"enter the Widhth and Height \n"; cin>>w>>h; Rect.setWidth(w); Rect.setHeight(h); class PaintCost { public: int getcost(int area) { int cost; cout<<"enter the paint cost for per inches \n"; cin>>cost; return area * cost; area = Rect.getArea(); cout << "Total area: " << Rect.getArea() << endl; cout << "Total paint cost: $" << Rect.getCost(area) << endl; return 0;

Hierarchical Inheritance: Hierarchical Inheritance: In this type of inheritance, multiple derived classes inherits from a single base class class A { //content of base class i.e., A class B :public A { //content of derived class i.e., B class C :public A { //content of derived class i.e., C class D :public A { //content of derived class i.e., D

Example for Hierarchical Inheritance: #include<iostream> using namespace std; class arithmetic{ protected: int op1,op2; public: void getop(int a, int b){ op1=a; op2=b; int main(){ sum s1; s1.getop(3,4); cout<<"addition is "<<s1.addition(); mul m1; m1.getop(3,4); cout<<"\n Multiplication is "<<m1.multiplication(); return 0; class sum: public arithmetic{ public: int addition(){ return op1+op2; class mul: public arithmetic{ public: int multiplication(){ return op1*op2;

Multilevel Inheritance: Multilevel Inheritance: class. class A { a Derived class is a base class for another //content of base class i.e., A class B :public A { //content of class i.e., B class C :public B { //content of derived class i.e., C

Example for Multilevel Inheritance: #include<iostream> using namespace std; class person{ protected: int age; char name[10]; public: void getdata(int a, char b[]){ age=a; for(int i=0;i<10;i++) name[i]=b[i]; class student: public person{ protected: char reg[10]; public: void getstu(){ cout<<"\n Enter the Register number :"; cin>>reg; void show(){ cout<<"\n student information \n "; cout<<"name :"<<name<<"\n"; cout<<"age :"<<age<<"\n"; cout<<"rollno :"<<reg<<"\n"; class nitr: public student{ protected: char branch[10]; int y; public: void getcol(){ cout<<"\n Enter the Branch :"; cin>>branch; cout<<"\n Enter the Year :"; cin>>y; void totaldata(){ cout<<"\n student information \n "; cout<<"name :"<<name<<"\n"; cout<<"age :"<<age<<"\n"; cout<<"rollno :"<<reg<<"\n"; cout<<"branch :"<<branch<<"\n"; cout<<"year :"<<y<<"\n";

int main(){ nitr p1; int a; char b[10]; cout<<"enter the name "; cin>>b; cout<<"enter the age"; cin>>a; p1.getdata(a,b); p1.getstu(); p1.getcol(); p1.totaldata(); return 0;

Hybrid Inheritance: Hybrid Inheritance (also known as Virtual Inheritance): Hybrid Inheritance is combination of Hierarchical and Mutilevel Inheritance. class A { //content of base class i.e., A class B :public A { //content of class i.e., B class C :public B { //content of derived class i.e., C Class D: public B, public C{

Try the following Example for hybrid Inheritance class Grandparent { //content of grandparent class class Child1 :public virtual Grandparent { //content of Child1 class class Child2 :public virtual Grandparent { //content of Child2 class class grandson :public Child1, public Child2 { //content of grandson class

Assignment 1 (Date: - 9/01/2017) 1. Write a sample C++ program demonstrating Variable scope. 2. Write a C++ program for finding factorial of a given number using recursion. 3. Write a C++ program to find the roots of a quadratic equation. Use switch or if statements to handle different values of the discriminant (b2 4ac). 4. Write a C++ program to create student class, which contains name, Register-Number & 5-subject marks as data members calculate average & grade by using member functions.

Assignment 2 (Date: - 16/01/2017) 1. Write a C++ program to calculate area of rectangle and square using constructor (default) and destructor 2. Write a C++ program to calculate area of circle using constructor (parameterized) and destructor 3. Write a C++ program to calculate area of triangle using constructor (copy) and destructor

Assignment 3 (Date: - 23/01/2017) Write C++ program to ready student information such as Name, DOB, Address (village/city, district, state and country, pin code), Education details like RegNO, Department, Course (b-tech, m-tech or dual degree) by illustrating following Inheritance concepts. 1. Single Inheritance 2. Multiple Inheritance 3. Hierarchical Inheritance 4. Multilevel Inheritance 5. Hybrid Inheritance (also known as Virtual Inheritance)