C++ Classes and Objects - code with Abuzar

Class in C++  ?

Aclass is a way to bind the data and it's associate functions together . it allows the data ( and fnctions ) to be hidden , if necessary , from external use . When defining a class we are creating a new abstract data type that can be treated like any other built - or data type . Generally , a class specification has two part .

1. Class declaration 
2. Class functions definitions 

The Class declare describe the data type and scope of it's memeber . The class function defines and describe how the class function are implemented .

The general form of class declaration is :

Class class_name

{

private :

variable declaration ;

Fuction declearation ;

Public :

variable declaration ;

Fuction declearation ;

};

Example of Class 

#include <iostream>
using namespace std;
class ClassA {
public:
	void set_a(int val);
	int get_a(void);

private:
	int a;
};
int ClassA::get_a(void) {
	return a;
}
void ClassA::set_a(int val) {
	a = val;
}
int main() {
	ClassA a;
	a.set_a(20); 
	cout << "Value of a is: " << a.get_a(); 
	return 0;
}

Example of Class 

Value of a is : 20 

The Class is similiar to Struct Declaration , the keyword of class specifies , follows of abstract data type class_name. The body of class is inclosed within braces and terminate by the semicolon . The class body declare of variable and functions . These functions and variable are collectively called class memeber . 

Ways of class memeber declared 

• Private :
• Public :
• Protected  :

Private :

private member work as it's name priavate(save) . It can access only accesss within a class it;s can not accessed outside the class and private member can use the data hiding in private in OOPS concept .

Example of Private member 

Public :

Public class memeber is  open classs member which data can be access by  outside the class .

Example of public members 

Protected :

Protected class is also a type of class in c++ .  A member declare in protected class is accessed by it's function and the other class is only derived it . It can not accessed by these two classes .

Source Code 

#include<iostream>

using namespace std;

class student 

{

Private ;

a = 10;

Public :

b = 20 ;

protected :

c = 30 ;

};

Objects  in C++ 

When a class is defined, only the specification for the object is defined; no memory or storage is allocated. To use the data and access functions defined in the class, you need to create objects.

Syntax :

Class name  Object_name ;

The declaration of an object is similiar to that of a variable of any basic type . The necessory memory space is allocated to an object at this stage . Note that , class specification , like a structure , provides only a  template and does not create any memory space for the object . 

Example of Object 

#include <iostream>

using namespace std;

class new 

{

// Access specifier

public:

// Data Members

string newname;

// Member Functions()

void printname()

{

cout << "newname is: " << newname;

}

};

int main() {

// Declare an object of class geeks

new  obj1;

// accessing data member

obj1.newname = "abuzar ";

// accessing member function

obj1.printname();

return 0;

}

Output 

New name is : Abuzar 

This article is contributed by Mohd Abuzar . if  you like code with abuzar and would like to contribute you can also write an article or mail at abuzar.abuzar.mohd325@gmail.com .

Please write comment if you find anything incorrect .