Access Modifier In C++ | Explain Access Modifier In C++ | Visibility Modes In C++| Access Modifier In C++ In Hindi

 

Access Modifier In C++

A pure virtual function (or abstract function) in C++ is a  virtual function for which we don’t have implementation, we only declare it. A pure virtual function is declared by assigning 0 in declaration.

Access Modifiers or Access Specifiers in a  class are used to set the accessibility of the class members. 

There are 3 types of access modifiers available in C++:

1.    Public

2.    Private

3.    Protected

 

Fig: Access Modifier In C++

      1.   Public:

 All the class members declared under public will be available to everyone. The data members and member functions declared public can be accessed by other classes too. The public members of a class can be accessed from anywhere in the program using the direct member access operator (.) with the object of that class.

Syntax:

class  base class

{

private:

-----------

public:

------------

protected:

-------------

};

class derived class: public base class

{

private:

-----------

public:

------------

};

Program:

#include<iostream.h>

#include<conio.h>

class bca

{

public:

void output()

{

cout<<”base class “;

}

};

class mca: public bca

{

public:

void output1()

{

cout<<”derived class”;

}

};

void main()

{

Mca a1;

a1.output();

getch();

}

Output:

Base class

 

    2.Private:

The class members declared as private can be accessed only by the functions inside the class. They are not allowed to be accessed directly by any object or function outside the class. Only the member functions or the  friend function  are allowed to access the private data members of a class.

Syntax:

class  base class

{

private:

-----------

public:

------------

protected:

-------------

};

class derived class: public base class

{

protected:

-----------

public:

------------

};

Program:

#include<iostream.h>

#include<conio.h>

class bca

{

private:

void output()

{

cout<<”base class “;

}

};

class mca: public bca

{

public:

void output1()

{

cout<<”derived class”;

}

};

void main()

{

Mca a1;

a1.output1();

getch();

}

Output:

Derived class

  

       3.Protected:

Protected access modifier is similar to that of private access modifiers, the difference is that the class member declared as Protected are inaccessible outside the class but they can be accessed by any subclass(derived class) of that class.

Syntax:

class  base class

{

private:

-----------

public:

------------

protected:

-------------

};

class derived class: public base class

{

protected:

-----------

public:

------------

};

Program:

#include<iostream.h>

#include<conio.h>

class bca

{

protected:

void output()

{

cout<<”base class “;

}

};

class mca: public bca

{

public:

void output1()

{

cout<<”derived class”;

}

};

void main()

{

Mca a1;

a1.output1();

getch();

}

Output:

Derived class