C++ programming language part- 61 Virtual Function and polymorphism ~ ICT & others Information

C++ programming language part- 61 Virtual Function and polymorphism

November 08, 2017 bappi ashraf

Virtual Function and polymorphism

Object-oriented programming refers to use of derived classes and virtual function. Suppose you have three televisions with three different VCRs. Those are requiring different and complex operation to use them. Then one day you have got a simple remote control that can operate all kinds of VCRs. That marvelous device represents the essence of object-oriented programming . That is using the same function from base class called virtual function.

Concept of Binding

Consider a class named furniture can be the base class from which the chair class is derived. So consider the statement: chair X; X.data_in(); . An object of the class chair named X is created and a member function called data_in(). In this case there is no ambiguity. consider the next statement again furniture *x; X->data_in(). Here is no ambiguity also. This process is called binding. In some situation may the type of object or pointer may not known at the time of compilation that are depended on the request of the user. since the object are dynamically created. This process is called dynamic binding, also known as late binding. consider the following statement.

furniture *f;

f=new chair;

f->data_in();

Virtual function with static polymorphism

Program 45_1

//virtual class.demo

class furniture //class defined

{private:

char color[10];

int h,w;

public:

void data_in()

{ cout<<"Type color,width & height \t";

cin>>color>>w>>h; }

void data_out()

{ cout<

void massage()

{ cout<<"This result from base class"<

};

class chair:public furniture

{ private:

int leg_no;

public:

void data_in() //member function

{furniture::data_in(); // Scope Resolution Operator

cout<<"Type number of legs\t";

cin>>leg_no; }

void data_out() //member function

{furniture::data_out(); // Scope Resolution Operator

cout<<" Number of legs are "<

void massage()

{ cout<<" This result from derived class "<

};

void main()

{furniture X;

furniture *f;

chair Y;

f=&X;

f->data_in();

f->data_out();

f->massage();

f=&Y;

f->data_in();

f->data_out();

f->massage(); }

Note: The both function will generate from base class. We can modify the code from base class furniture.

virtual void data_in(); virtual void data_out();virtual void massage();

Now it will generate from both base and derrived.

part: 01 Programming Language

part: 02 Compiler

part: 03 Programming Logic

part: 04 Data Type

part: 05 Programming in C++

part: 06 Data Type

part: 07 Get Input from keyboard

part: 08 Operators

part: 09 Arithmetic AssignmentOperators

part: 10 Identifies of Characters

part: 11 do.. while loop

part: 12 unary operators( Incrementand decrement)

part: 13 Decrement

part: 14 for loop

part: 16 Conditional/ternary Operator

part: 17 Break

part: 18 The continue statementforces the next iteration of the loop to take place.

part: 19 Arrays

part: 20 Array Address

part: 21 Arrays and Pointer

part: 22 Two dimensional array

part: 23 Function

part: 24 Function Argument

part: 25 Calling Function

part: 26 Return Values

part: 27 Over Loading Function

part: 29 More about function andothers

part: 30 Passing arrays to function

part: 31 Dynamic memory allocation

part: 32 Library function

part: 33 User define mathematicalfunction (square)

part: 34 I/O Function

part: 35 Boolean Functions

part: 36 Look here's two differentuser define Boolean Functions

part: 37 Function Scope

part: 38 String

part: 39 String I/O

part: 40 Some dafault member function

part: 41 Standard String-Handlingfunction

part: 42 String Array

part: 43 User defined data type

part: 45 Data Storage Type

part: 46 Sratic storage type

part: 47 Extern storage type

part: 48 Classes and Objects

part: 49 Scope Resolution Operator

part: 50 Constructor

part: 51 Destructor

part: 52 Inheritance

part: 53 Overriding Base ClassMembers

part: 54 Scope Resolution with OverriddenMembers

part: 55 Base Class Initialization

part: 56 Multiple Inheritance

part: 57 Protected base ClassInheritance

part- 58 Ambiguity of MultipleClasses

part- 59 Virtual Base Class

part- 60 More about Constructor andDestructor

part- 61 Virtual Function andpolymorphism

part- 62 Virtual function withdynamic polymorphism

part- 63 Streams

part- 64 File Input and Output withabstract data types

part- 65 Writing and Readingcharacter using binary functions

part- 66 The get() function

part- 67 String Input

part- 68 Integer Input and Output

part- 69 File Pointers

part- 70 More abuot Integer Input and Output

part- 71 Exercise:

part- 72 Operator overloading

part- 73 Look here is a program witha class and overload the ==,>,< and += operators

part- 74 Linked List

part- 75 Representing a Node

part- 76 Inserting and Traversing a Node

part- 77 Deleting a Node

part- 78 More about Linked List

part- 79 Programming Logic andTechnique

part- 81 Programming Logic and Technique:

part- 82 Programming Logic andTechnique:

part- 83 Programming Logic andTechnique:

part- 84 Programming Logic andTechnique:

part- 85 Programming Logic and Technique:

Part- 86 assign the content of twostring