int day;
int count;
int divisor;
int answer;

// smallobj.cpp
// demonstrates a small, simple object

#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////
class smallobj //define a class
{
private:
int somedata; //class data
public:
void setdata(int d) //member function to set data
{ somedata = d; }
void showdata() //member function to display data
{ cout << “Data is “ << somedata << endl; }
};
////////////////////////////////////////////////////////////////
int main()
{
smallobj s1, s2; //define two objects of class smallobj

s1.setdata(1066); //call member function to set data
s2.setdata(1776);

s1.showdata(); //call member function to display data
s2.showdata();
return 0;
}

 Data is 1066 ← object s1 displayed this
Data is 1776 ← object s2 displayed this

class smallobj //define a class
{
private:
int somedata;			 //class data
public:
void setdata(int d) 		//member function to set data
{ somedata = d; }
void showdata() 		//member function to display data
{ cout << “\nData is “ << somedata; }
};

void setdata(int d)
{
somedata = d;
}

void showdata()
{
cout << “\nData is “ << somedata;
}

smallobj s1, s2;

s1.setdata(1066);
s2.setdata(1776);

setdata(1066);

 s1.setdata(1066);

 s2.setdata(1776);

s1.showdata();
s2.showdata();

s1.showdata();

// objpart.cpp
// widget part as an object
#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////
class part //define class
{
private:
int modelnumber; 	//ID number of widget
int partnumber; 	//ID number of widget part
float cost; 		//cost of part
public:
void setpart(int mn, int pn, float c) //set data
{
modelnumber = mn;
partnumber = pn;
cost = c;
}
void showpart() //display data
{
cout << “Model “ << modelnumber;
cout << “, part “ << partnumber;
cout << “, costs $” << cost << endl;
}
};
////////////////////////////////////////////////////////////////
int main()
{
part part1; 		//define object
// of class part
part1.setpart(6244, 373, 217.55F); 		//call member function
part1.showpart(); 				//call member function
return 0;
}

Model 6244, part 373, costs $217.55

// englobj.cpp
// objects using English measurements
#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////
class Distance						 //English Distance class
{
private:
int feet;				// data items
float inches;
public:
void setdist(int ft, float in) 			//set Distance to args
{ feet = ft; inches = in; }
void getdist() 					//get length from user
{
cout << “\nEnter feet: “; cin >> feet;
cout << “Enter inches: “; cin >> inches;
}
void showdist() 				//display distance
{ cout << feet << “\’-” << inches << ‘\”’; }
};
////////////////////////////////////////////////////////////////
int main()
{
Distance dist1, dist2; 		//define two lengths (objects), as Data Type
dist1.setdist(11, 6.25); 		//set dist1
dist2.getdist(); //get dist2 from user
//display lengths
cout << “\ndist1 = “; dist1.showdist();
cout << “\ndist2 = “; dist2.showdist();
cout << endl;
return 0;
}

 Enter feet: 10
Enter inches: 4.75

dist1 = 11’-6.25” ← provided by arguments
dist2 = 10’-4.75” ← input by the user

// counter.cpp
// object represents a counter variable
#include <iostream>
using namespace std;
////////////////////////////////////////////////////////////////
class Counter
{
private:
unsigned int count; //count
public:
Counter() : count(0) //constructor
{ /*empty body*/ }
void inc_count() //increment count
{ count++; }
int get_count() //return count
{ return count; }
};
////////////////////////////////////////////////////////////////
int main()
{
Counter c1, c2; 				//define and initialize

cout << “\nc1=” << c1.get_count(); 	//display
cout << “\nc2=” << c2.get_count();

c1.inc_count();				 //increment c1
c2.inc_count();				 //increment c2
c2.inc_count(); 				//increment c2

cout << “\nc1=” << c1.get_count(); 	//display again
cout << “\nc2=” << c2.get_count();
cout << endl;
return 0;
}

Counter c1; 		//every time we do this,
c1.zero_count(); 	//we must do this too

Counter c1, c2;

 Counter()
{ count = 0; }

 Counter() : count(0)		 //constructor
{ /*empty body*/ }

someClass() : m1(7), m2(33), m2(4) ← initializer list
{ }

 c1=0
c2=0
c1=1
c2=2

I’m the constructor
I’m the constructor
c1=0
c2=0
c1=1
c2=2

 Counter c1, c2;

class Class-name
{
private: // its optional to write private access specifier
data-member;
data-member;
member-function
protected:
data-member;
data-member;
member-function
public:
data-member;
data-member;
member-function
};
:
class_name List-of-objects;

class HUMAN
{
int HIEGHT,EYECOLOR,AGE; 	// data-member
char TYPE; 				// M: Man
// W: Women
public:
void input(); 				// member-function
void output();
};
:
HUMAN Steve, Jordan ;

Program 1.1
/***********************************************************************
Program 1(1).cpp
Explaining the concept of classes and objects
***********************************************************************/
// Header files
# include <iostream.h>
# include <stdio.h>

// Declration of class hospital
class hospital
{
private:
int patientno,wardno;		 //private data members
char patient_name[20];
public:
void register_patient(); 	//public member function prototype

void showstatus()		 //public member function declaration
{
cout<<patientno<<":"<<patient_name<<":"<<wardno<<endl;
}

}; //semicolon is a must



/***********************************************************************
Name: register_patient
Class: hospital
Purpose: Input patient information
***********************************************************************/
void hospital::register_patient()
{
cout<<"patient no ?";
cin>>patientno;

cout<<"name ?";
gets(patient_name);

cout<<"Ward no ?";
cin>>wardno;
}

// Main function
void main()
{
hospital p1,p2;
p1.register_patient();
p2.register_patient();

p1.showstatus();
p2.showstatus();
}

// cin>>p1.wardno; 		** not accessible as wardno is a private member
// cin>>p1.patientno; 		**not accessible as patientno is a private member

{
private:
………………………… //private members
………………………...

public:
……………………… // public members
……………………...
friend data_type function_name(); // Declaration of friend function
};

 
Program 1.2

/***********************************************************************
Program 2(2).cpp
The program displays objects being passed as arguments for class time and objects undergoing basic arithmetic operations.
***********************************************************************/
// Header Files
# include <iostream.h>
# include <conio.h>

class time
{
int hrs,mins;

public:
// Function to get time from the user
void gettime()
{
cout<<"Enter the hours !";
cin>>hrs;

cout<<" \nEnter the minutes !! ";
cin>>mins;
}

void settime (int h ,int m)
{
hrs=h; mins=m;
}

// Function to show time on the screen
void showtime()
{
cout<<hrs<<":"<<mins<<endl;
}

// Function to sum two objects of class time
void sum (time t1,time t2)
{
int minutes=t1.mins +t2.mins;
hrs = t1.hrs+t2.hrs +minutes/60;
mins=minutes%60;
}
};

// Main function
void main()
{
time t1,t2,t3;

t1.gettime(); 			// Call to function gettime
t2.settime(3,45);		 // Call to function settime
t3.sum(t1,t2);			 // Objects being passed as arguments

cout<<"\nt1=";
t1.showtime(); 		// Call to function showtime

cout<<"t2=";
t2.showtime();

cout<<"t3=";
t3.showtime();
}

 Enter the hours !10
Enter the minutes !! 10

t1=10:10
t2=3:45
t3=13:55