Object Oriented Programming Inheritance

Chapter 4
Example 1 : Program to print value and address of a variable
#include <iostream.h>
#include<conio.h>
void main()
{
int i=5;
clrscr();
cout<<"Value of i : "<<i<<"\n";
cout<<"Address of i : "<<&i;
getch();
}
Sample input and output
Value of i : 5
Address of i : 0x8fc5fff4

Example 2 : A copy() function for arrays
#include <iostream.h>
double* copy(double [], int);
void print(double [], int);
void main()
{
double a[8] = {22.2, 33.3, 44.4, 55.5, 66.6, 77.7, 88.8, 99.9};
print(a, 8);
double* b = copy(a, 8);
a[2] = a[4] = 11.1;
print(a, 8);
print(b, 8);
}
double* copy(double a[], int n)
{
double* p = new double[n];
for (int i = 0; i < n; i++)
p[i] = a[i];
return p;
}
void print(double a[], int n)
{
for (int i = 0; i < n; i++)
cout << a[i] << " ";
cout << endl;

}
Example 3 :
#include <iostream.h>
struct employee
{
char name[30];
int code;
int salary;
}emp[30];
main()
{
int i;
for(i=0;i<30;i++)
{
cout<<"Enter the name of the employee\n";
cin>>emp[i].name;
cout<<"Entre the code of employee\n";
cin>>emp[i].code;
cout<<"Enter the salary\n";
cin>>emp[i].salary;
}
for(i=0;i<30;i++)
{
if(emp[i].salary>10000)
{
cout<< " Employee having salary > 10,000 : " <<emp[i].name ;
}
}
}
Example 4 :
#include<iostream.h>
#include<conio.h>
#include<string.h>
struct player
{
char name[30],country[30];
int No_Of_Matches;
float avg;
}
p[50];

void main()
{
int i,j,temp;
char str[30];
clrscr();
for(i=0;i<50;i++)
{
cout<<"Enter the name of player: ";
cin>>p[i].name;
cout<<"Enter the name of country of player: ";
cin>>p[i].country;
cout<<"Enter the number of matches he had played: ";
cin>>p[i].No_Of_Matches;
cout<<"Enter the Batting avg : ";
cin>>p[i].avg;
}
for(i=0;i<50;i++)
{
for(j=1;j<50;j++)
{
if(p[i].avg<p[j].avg)
{
temp=p[i].No_Of_Matches;
p[i].No_Of_Matches=p[j].No_Of_Matches;
p[j].No_Of_Matches=temp;
temp=p[i].avg;
p[i].avg=p[j].avg;
p[j].avg=temp;
strcpy(str,p[i].name);
strcpy(p[i].name,p[j].name);
strcpy(p[j].name,str);
strcpy(str,p[i].country);
strcpy(p[i].country,p[j].country);
strcpy(p[j].country,str);
}
}
}
for(i=0;i<50;i++)
{
cout<<"\nThe name of player: "<<p[i].name;
cout<<"\nThe name of country of player: "<<p[i].country;
cout<<"\nThe number of matches he had played:
"<<p[i].No_Of_Matches;
cout<<"\nThe Batting avg : "<<p[i].avg;

}
}

Example 5 :
#include<iostream.h>
#include<conio.h>
#include<string.h>
struct student
{
char name[20];
int m;
} s[5];
void main()
{
int i,j,temp;
char temp1[20];
for(i=0;i<5;i++)
{
cout<<"\n Enter the name of student "<<i;
cin>>s[i].name;
cout<<"\n Enter the marks of student "<<(i+1);
cin>>s[i].m;
}
for(i=0;i<5;i++)
{
for(j=0;j<5;j++)
{
if(s[i].m>s[j].m)
{
temp=s[j].m;
s[j].m=s[i].m;
s[i].m=temp;
strcpy(temp1,s[j].name);
strcpy(s[j].name,s[i].name);
strcpy(s[i].name,temp1);
}
}
for(i=0;i<5;i++)
{
cout<<"\n Name : "<<s[i].name<<"\t Marks : "<<s[i].m;
}
getch();

}

}

Example 6 : Program for Use of Union
#include <iostream.h>
#include <conio.h>
void main ()
{
union sample
/* union declaration */
{
int a ;
char b ;
float c ;
};
union sample s ; /* union variable declaration */
clrscr () ;
/* stored as integer and retrieved as integer */
s.a = 10 ;
cout<< "a = "<<s.a ;
/* stored as character and retrieved as character */
s.b = 'x' ;
cout<<"\nb = "<<s.b ;
/* stored as float and retrieved as float */
s.c = 100.34 ;
cout<<"\nc = "<< s.c;
/*stored as float and retrieved as integer-a wrong way*/
s.c = 1.567 ;
cout<<"\na = "<<s.a ;
getch () ;
}

Example 7 :
#include<iostream.h>
#include<string.h>
#include<conio.h>
struct student
{
char name[20],DOB[8];
int RollNumber,m;
}s[5];

void

main()
{
int i,j,temp;
char temp1[20];
for(i=0;i<5;i++)
{
cout<<"\n Enter the name of student : "<<i;
cin>>s[i].name;
cout<<"\n Enter the marks of student : "<<i;
cin>>s[i].m;
cout<<"\n Enter the DOB of student : "<<i;
cin>>s[i].DOB;
cout<<"\n Enter the RollNumber of student : "<<i;
cin>>s[i].RollNumber;
}
for(i=0;i<5;i++)
{
for(j=0;j<5;j++)
{
if(s[i].m>s[j].m)
{
temp=s[j].m;
s[j].m=s[i].m;
s[i].m=temp;
temp=s[j].RollNumber;
s[j]. RollNumber =s[i]. RollNumber;
s[i]. RollNumber =temp;
strcpy(temp1,s[j].DOB);
strcpy(s[j].DOB,s[i].DOB);
strcpy(s[i].DOB,temp1);
strcpy(temp1,s[j].name);
strcpy(s[j].name,s[i].name);
strcpy(s[i].name,temp1);
}
}
for(i=0;i<5;i++)
{

cout<<"\n Name : "<<s[i].name<<" \t Marks : "<<s[i].m<<"\tDOB :
"<<s[i].RollNumber;
}
getch();
return(0);
}}

Example 8 : Program for dynamic implementation of linked list
#include<iostream.h>
#include<conio.h>
struct node
{
int info;
struct node *next;
};
struct node *list=0;
struct node * getnode(void)
{
/*function to allocate memory for new node*/
return((struct node*)new(struct node));
}/*end getnode*/
void freenode(struct node *p)
{
/*free dynamically allocated memory*/
delete(p);
}/*end freenode*/
void display()
{
/*display all nodes*/
int i;
struct node *t;
t=list;
if(t==NULL)
cout<<"\nThe linked list is empty";
else
{
cout<<"\n";
while(t!=NULL)
{
cout<<"-->|"<<t->info<<"|";
t=t->next;
}
}
}/*end display*/
void insertbeg(int x)
{
/*insert new element at the beginning of linked list*/
struct node *q;
q=getnode();
q->info=x;

q->next=list;
list=q;
display();
}/*end insertbeg*/
void insertend(int x)
{
/*insert new element at the end of linked list*/
struct node *q,*temp;
q=getnode();
q->info=x;
q->next=NULL;
temp=list;
if(temp==NULL)
list=q;
else
{
while(temp->next!=NULL)
temp=temp->next;
temp->next=q;
}
display();
}/*void insertend*/
void insafter(int p,int x)
{
/*insert new element after a specific node*/
struct node *q,*t;
int i;
if(list==NULL)
cout<<"\nInvalid insertion";
else
{
t=list;
for(i=0;i<p-1;i++)
t=t->next;
q=getnode();
q->info=x;
q->next=t->next;
t->next=q;
display();
}
}/*end insafter*/
void delafter(int p)
{
/*delete new element after a specific node*/
int x,i;

struct node *t,*q;
t=list;
for(i=0;i<p-1;i++)
t=t->next;
if((list==NULL)||(t->next==NULL))
cout<<"\nInvalid deletion(list is empty/end of list)";
else
{
q=t->next;
x=q->info;
t->next=q->next;
freenode(q);
cout<<"\nThe deleted element is "<<x;
}
display();
}/*end delafter*/
void deletebeg(void)
{
/*delete a node from the beginning of the linked list*/
int x;
struct node *q;
q=list;
if(list==NULL)
cout<<"\nThe linked list is empty";
else
{
x=q->info;
list=q->next;
cout<<"\nThe deleted element is "<<x;
freenode(q);
display();
}
}/*end deletebeg*/
void deleteend(void)
{
/*delete a node from the end of the linked list*/
struct node *q,*temp;
int x;
q=list;
if(q==NULL)
cout<<"\nThe linked list is empty";
else
{
if(q->next==NULL)
{
x=q->info;

list=NULL;
}
else
{
while(q->next!=NULL)
{
temp=q;
q=q->next;
}
x=q->info;
temp->next=NULL;
}
cout<<"\nThe deleted element is "<<x;
freenode(q);
}
display();
}/*end deleteend*/
void insloc(int p,int x)
{
/*insert new node at a specific location*/
int t,i;
struct node *q,*temp;
temp=list;
for(i=0;i<(p-2);i++)
{
temp=temp->next;
if(temp==NULL)
{
cout<<"\nThere are less than "<<p<<"elements in list "<<p;
break;
}
}
if(temp!=NULL)
{
q=getnode();
q->info=x;
q->next=temp->next;
temp->next=q;
}
display();
}/*end insloc*/
void delloc(int p)
{
/*delete a node from a specific location*/
int i;
struct node *temp,*t;

temp=list;
if(p==1)
list=list->next;
for(i=0;i<p-1;i++)
{
if(temp->next==NULL)
{
cout<<"\nThere are less than "<<p<<"elements in list "<<p;
break;
}
t=temp;
temp=temp->next;
}
if(temp->next!=NULL)
{
cout<<"\nThe deleted element is "<<temp->info;
t->next=temp->next;
freenode(temp);
}
display();
}/*end delloc*/
void search(int x)
{
/*search a node in linked list*/
struct node *t;
int i;
for(t=list,i=0;t!=NULL;t=t->next,i++)
{
if(t->info==x)
{
cout<<"\nPosition of element "<<x<<"is "<<i+1<<endl;
break;
}
}
if(t==NULL)
cout<<"\nElement not found";
display();
}/*end search*/
void main()
{
struct node * getnode(void);
int ch,p,info,x;
char ans='y';
clrscr();
cout<<"\n\tDynamic Linked List";

cout<<"\n1.Insert after a node";
cout<<"\n2.Delete after a node";
cout<<"\n3.Insert at begining ";
cout<<"\n4.Delete at begining ";
cout<<"\n5.Insert at end ";
cout<<"\n6.Delete at end ";
cout<<"\n7.Insert at location";
cout<<"\n8.Delete at location";
cout<<"\n9.Search an element";
back:cout<<"\nEnter ur choice : ";
cin>>ch;
switch(ch)
{
case 1: cout<<"\nEnter the node no : ";
cin>>p;
cout<<"\nEnter the info : ";
cin>>x;
insafter(p,x);
break;
case 2: cout<<"\nEnter the node no : ";
cin>>p;
delafter(p);
break;
case 3: cout<<"\nEnter the info : ";
cin>>x;
insertbeg(x);
break;
case 4: deletebeg();
break;
case 5: cout<<"\nEnter the info : ";
cin>>x;
insertend(x);
break;
case 6: deleteend();
break;
case 7: cout<<"\nEnter the node no : ";
cin>>p;
cout<<"\nEnter the info : ";
cin>>x;
insloc(p,x);
break;
case 8: cout<<"\nEnter the node no : ";
cin>>p;
delloc(p);
break;
case 9 :cout<<"\nEnter the element : ";

cin>>x;
search(x);
break;
case 10: display();
break;
default:cout<<"\nWrong choice ";
}
cout<<"\nDo u want to continue(y/n)?";
cin>>ans;
if(ans=='y')
goto back;
}/*end main*/

Example 9 : Program for Searching for an address
#include <iostream.h>
int* location(int[],int,int);
void main()
{ int a[8] = {22, 33, 44, 55, 66, 77, 88, 99}, * p=0, n;
do
{ cin >> n;
if (p == location(a, 8, n)) cout << p << ", " << *p << endl;
else cout << n << " was not found.\n";
} while (n > 0);
}
int* location(int a[], int n, int target)
{ for (int i = 0; i < n; i++)
if (a[i] == target) return &a[i];
return NULL;
}
Example 10 :
#include <iostream.h>
#include <conio.h>
struct COMPUTER
{
char CPUtype[15],CDROM_type[10],mouse_type[15];
char key_board_type[15],SVGA_monitor_make[15];
int SDRAM_size,HDD_size;
float clock_speed,CDROM_speed;
}
comp[50];

void main()
{
int i;
clrscr();
for(i=0;i<50;i++)
{
cout<<"\nEnter CPU tpye, CDROM_type, mouse_type";
cin>>comp[i].CPUtype>>comp[i].CDROM_type>>comp[i].mouse_type;
cout<<"Enter key_board_type, SVGA_monitor_make";
cin>>comp[i].key_board_type>>comp[i].SVGA_monitor_make;
cout<<"Enter SDRAM_size, HDD_size";
cin>>comp[i].SDRAM_size>>comp[i].HDD_size;
cout<<"Enter clock_speed, CDROM_speed";
cin>>comp[i].clock_speed>>comp[i].CDROM_speed;
}
for(i=0;i<50;i++)
{
if(comp[i].HDD_size> 8)
{
cout<<"CPU type is "<<comp[i].CPUtype;
}
}
}

Example 11 :
#include<iostream.h>
#include<string.h>
#include<conio.h>
void swap (char p, char q)
{
char c ;
c=p;
p=q;
q=c;
}
void swap1 (char *p, char *q)
{
char c ;
c = *p ;
*p = *q ;
*q = c ;
}

void perm (char *a, int m, int n)
{
if (m == n)
{
for (int i = 0 ; i < n ; i ++)
cout<<a [ i ] ;
}
else
{
for (int j = n ; j<=m;j++)
{
swap(a[j],a[n]) ;
perm(a,m,n+1);
swap1(&a[j],&a[n]);
}
}
}
void main( )
{
char *a = "India";
perm(a, strlen(a)-1, 0);
getch( );
}

Example 12 :
#include<iostream.h>
#include<conio.h>
#include<string.h>
struct student
{
char name[20],DOB[8];
int Marks,SeatNo;
}
s[5];
main()
{
int i,j,temp;
char temp1[20];
for(i=0;i<5;i++)
{

cout<<"\n Enter the name of student : " <<i;
cin>>s[i].name;
cout<<"\n Enter the SeatNo of student : "<<i;
cin>>s[i].SeatNo;
cout<<"\n Enter the DOB of student : "<<i;
cin>>s[i].DOB;
cout<<"\n Enter the Marks of student : "<<i;
cin>>s[i].Marks;
}
for(i=0;i<5;i++)
{
for(j=0;j<5;j++)
{
if(s[i].SeatNo>s[j].SeatNo)
{
temp=s[j].SeatNo;
s[j].SeatNo=s[i].SeatNo;
s[i].SeatNo=temp;
temp=s[j].Marks;
s[j]. Marks =s[i]. Marks;
s[i]. Marks =temp;
strcpy(temp1,s[j].DOB);
strcpy(s[j].DOB,s[i].DOB);
strcpy(s[i].DOB,temp1);
strcpy(temp1,s[j].name);
strcpy(s[j].name,s[i].name);
strcpy(s[i].name,temp1);
}
}
for(i=0;i<5;i++)
{
cout<<"\n Name : "<< s[i].name<<"\t SeatNo :
"<<s[i].SeatNo<<"\tDOB : "
<<s[i].DOB <<"\t Marks : "<<s[i].Marks;
}
}
getch();
return(0);
}
Example 13 : Function returning a Pointer

#include <iostream.h>
#include <conio.h>
void main ()
{
int *square ( int *a ) ;
int i, *result ;
clrscr () ;
cout<<"i = " ;
cin>>i;
result = square ( &i ) ;
cout<<"square ( i ) : "<<*result ;
}
int *square ( int *a )
{
*a = *a * *a ;
return ( a );
}
Example 14 : Program for integer pointer type
#include <iostream.h>
#include<conio.h>
void main()
{
int i=5;
int *p;
clrscr();
p=&i;
cout<<"Value of i : "<<i;
cout<<"\nValue of i : "<<*p;
cout<<"\nValue of i : "<<*(&i)<<"\n";
cout<<"\nAddress of i : "<<&i;
cout<<"\nAddress of i : "<<p<<"\n";
cout<<"\nValue of p: "<<p;
cout<<"\nValue of p: "<<*(&p);
cout<<"\nAddress of p: "<<&p;
getch();
}

Example 15 : Program for Other Pointer types
#include <iostream.h>
#include <conio.h>
void main ( )
{
char *a, b ;
float *c, d ;
double *e, f ;
clrscr ( ) ;
b = 'x' ;
d = 1.2 ;
f = 100.009 ;
cout<< "\nValue of b : "<< b ;
a = &b ;
cout<< "\nValue of location pointed by a : "<< *a ;
cout<<"\nValue of d : "<< d ;
c = &d ;
cout<<"\nValue of location pointed by c : "<< *c ;
cout<<"\nValue of f v : "<< f ;
e = &f ;
cout<<"\nValue of location pointed by : "<< *e ;
}
Example 16 :
#include <iostream.h>
#include<conio.h>
void main()
{
int i=5,*p,**pp;
clrscr();
p=&i;
pp=&p;
cout<<"Value of i : "<<i;
cout<<"\nValue of i : "<<*p;
cout<<"\nValue of i : "<<*(&i);
cout<<"\nValue of i : "<<**pp;
cout<<"\nValue of i : "<<i<<"\n";

cout<<"\nAddress of i : "<<&i;
cout<<"\nAddress of i : "<<p<<"\n";
cout<<"\nValue of p : "<<p;
cout<<"\nValue of p : "<<*(&p);
cout<<"\nValue of p : "<<*pp<<"\n";
cout<<"\nAddress of p : "<<&p;
cout<<"\nAddress of p : "<<pp<<"\n";
cout<<"\nValue of pp : "<<pp<<"\n";
cout<<"\nAddress of pp : "<<&pp;
getch();
}

Example 17 : Program for Pointers and Array
#include <iostream.h>
#include <conio.h>
void main ()
{
int array[5] = { 11, -2, 30, 41, 15 } ;
int *pointer ;
clrscr () ;
pointer = &array[0] ;
cout<<"The array elements are.....";
while ( pointer < pointer + 5 )
{
cout<<*pointer<<"\n";
pointer++ ;
}
getch () ;
}

Example 18 : Program for Array name as a pointer
#include <iostream.h>
#include <conio.h>
void main ()
{

int array[5] = { 11, -2, 30, 41, 15 } ;
int *pointer ;
clrscr () ;
pointer = array ; /* Array name is used as a pointer */
cout<<"The array elements are...." ;
while ( pointer < pointer + 5 )
{
cout<<*pointer<<endl;
pointer++ ;
}
getch () ;
}

Example 19 : Program for Array name as a pointer - second example
#include <iostream.h>
#include <conio.h>
void main ()
{
void multiply_by_2 ( int a[] ) ;
int array[5] = { 11, -2, 30, 41, 15 } ;
int *start, *end ;
clrscr () ;
multiply_by_2 ( array ) ;/* name of the array is passed to function */
start = array ;
end = array + 5 ;
cout<<"The array elements are....." ;
for ( ; start < end ; start++ )
cout<<*start<<endl;
getch () ;
}
void multiply_by_2 ( int a[] )
{
int i ;
for ( i = 0; i < 5; i++ )
a[i] = a[i] * 2 ;
}
Example 20 :
#include <iostream.h>
#include <conio.h>
void main ()

{
double (*a)(); /* Pointer to Function declaration */
double function () ;
double result ;
clrscr () ;
a = function ; /* Pointer to Function assignment */
result = (*a)() ;

/* Function call using pointer 'a' */

cout<<"Result = "<<result ;
getch () ;
}
double function ()
{
double a, b ;
a = 10.5 ;
b = 20.3 ;
a=a+b;
return ( a ) ;
}
Example 21 : Program for Pointer to Function ( with arguments )
#include <iostream.h>
#include <conio.h>
void main ()
{
double (*a)( double, int ); /* Pointer to Function declaration */
double function ( double a, int b ) ;
double result ;
clrscr () ;
a = function ;

/* Pointer to Function assignment */

result = (*a)( 12.7, 23 ) ; /* Function call using pointer 'a' */
cout<<"Result = "<<result ;
getch () ;
}
double function ( double a, int b )

{
a=a+b;
return ( a ) ;
}

Example 22 : Using a reference as a synonym
#include <iostream.h>
void main()
{
int n=44;
int& rn=n; // r is a synonym for n
cout << "n = " << n << ", rn = " << rn << endl;
--n;
cout << "n = " << n << ", rn = " << rn << endl;
rn *= 2;
cout << "n = " << n << ", rn = " << rn << endl;
}

Example 23 : Program to illustrate use of structure
#include<iostream.h>
#include<conio.h>
void main()
{
struct book
{
char name;
float price;
int pages;
};
struct book b1,b2,b3;
cout<<"\nEnter names,prices & no of pages of 3 books";
cin>>b1.name>>b1.price>>b1.pages;
cin>>b2.name>>b2.price>>b2.pages;
cin>>b3.name>>b3.price>>b3.pages;
cout<<"\nAnd this is what you entered";
cout<<"\n"<<b1.name<<"\t"<<b1.price<<"\t"<<b1.pages;
cout<<"\n"<<b2.name<<"\t"<<b2.price<<"\t"<<b2.pages;
cout<<"\n"<<b3.name<<"\t"<<b3.price<<"\t"<<b3.pages;
}

Example 24 : Structure within Structure
#include <iostream.h>
#include <conio.h>
void main()
{
struct date
{
int day ;
int month ;
int year ;
};
struct item
{
char *item_name ;
int price ;
struct date manufacture_date ; /* structure within structure
Declaration */
};
struct item a ;
clrscr () ;
a.item_name = "Soap" ;
a.price = 10 ;
a.manufacture_date.day = 2; /*structure within structure*/
a.manufacture_date.month = 11 ; /* initialisation */
a.manufacture_date.year = 1999 ;
cout<<"Item Details :\n";
cout<<"\nName : "<<a.item_name;
cout<<"\nPrice : "<<a.price;
cout<<"\nDate : "<<a.manufacture_date.day;
cout<<"/"<<a.manufacture_date.month;
cout<<"/"<<a.manufacture_date.year;
getch () ;
}

Example 25 : Program for Structure local to a function

#include <iostream.h>
#include <conio.h>
void main ( )
{
void function ( ) ;
clrscr ( ) ;
function ( ) ;
getch ( ) ;
}
void function ( )
{
struct date
{
int day ;
int month ;
int year ;
};
struct date todays_date = { 22, 6, 2007 } ;
cout<<"Today's Date : ";
cout<<todays_date.day;
cout<<" "<<todays_date.month;
cout<<" "<<todays_date.year;
}

Example 26 : Program for Structure passed to a function ( by Value )
#include <iostream.h>
#include <conio.h>
struct student
{
int student_roll_no ;
int marks_in_subject1 ;
int marks_in_subject2 ;
};
void main ( )
{
void print_structure ( struct student s1 ) ;
float find_average ( struct student s1 ) ;
struct student s1 = { 3032, 89, 78 } ;
clrscr ( );
/* Structure variable passed by value */
print_structure ( s1 ) ;
cout<<"Average Marks = "<<find_average ( s1 ) ;

getch ( ) ;
}
void print_structure ( struct student s1 )
{
cout<<"Student Record : \n";
cout<<"Roll Number : "<<s1.student_roll_no<<endl;
cout<<"Subject 1 marks : "<<s1.marks_in_subject1<<endl;
cout<<"Subject 2 marks : "<<s1.marks_in_subject2<<endl;
}
float find_average ( struct student s1 )
{
float average ;
average = s1.marks_in_subject1 + s1.marks_in_subject2 ;
average = average / 2 ;
return ( average ) ;
}

Example 27 : Function returning a Structure
#include <iostream.h>
#include <conio.h>
struct student
{
int student_roll_no ;
int marks_in_subject1 ;
int marks_in_subject2 ;
};
void main ()
{
struct student function () ;
struct student t ;
float result ;
clrscr () ;
t = function () ;
cout<<"Student Record : \n";
cout<<"Roll Number : "<<t.student_roll_no;
cout<<"Subject 1 marks : "<< t.marks_in_subject1 ;
cout<<"Subject 2 marks : "<< t.marks_in_subject2 ;
getch () ;
}
struct student function ( )
{
struct student s1 = { 3032, 89, 78 } ;
return ( s1 ) ;

}

Example 28 : Program : Array as a member of a Structure
#include <iostream.h>
#include <conio.h>
struct employee
{
char name[10] ;
char address[15] ;
long int telephone_numbers[5] ;
};
void main ( )
{
struct employee input ( ) ;
struct employee e ;
int i ;
clrscr ( ) ;
e = input ( ) ;
cout<<"\n\nEmployee Personal Information displayed... \n";
cout<<"\nName
: "<<e.name ;
cout<<"\nAddress : "<<e.address ;
cout<<"\nTelephone Numbers : ";
for ( i = 0; e.telephone_numbers[i] > 0 && i < 5; i++ )
cout<<"\n"<<e.telephone_numbers[i] ;
getch ( ) ;
}
struct employee input ( )
{
struct employee temp ;
long int no;
int i ;
cout<<"Input the following -\n";
cout<<"Name : ";
cin>>temp.name ;
cout<<"Address : ";
cin>>temp.address;
cout<<"Telephone Numbers :\n";
cout<<"(terminate with -ve number,\n" ;
cout<<"if want to enter less than 5 telephone numbers)\n";
i = 0;

cin>>no ;
/*
User can enter either 5 differrent telephone numbers or less.
If he enters less than 5 telephone numbers then he may terminate by entering
negative number */
while ( no > 0 && i < 4 )
{
temp.telephone_numbers[i] = no ;
i++ ;
//scanf("%ld",&no) ;
cin>>no;
}
temp.telephone_numbers[i] = no ;
return ( temp ) ;
}
Example 29 : Program for Array of Structures
#include <iostream.h>
#include <conio.h>
struct employee
{
char name[10] ;
char address[15] ;
long int telephone_numbers[5] ;
};
void main ( )
{
struct employee input ( ) ;
struct employee e[5] ;
int i, j, n ;
clrscr ( ) ;
cout<<"Enter Number of Employees ( less than 5 ) : ";
cin>>n ;
for ( i = 0; i < n; i++ )
e[i] = input ( ) ;
clrscr ( ) ;
cout<<"\n\nEmployee Personal Information displayed... \n";
for ( i = 0; i < n; i++ )
{
cout<<"\nName
: "<<e[i].name<<endl;
cout<<"Address : "<<e[i].address<<endl;
cout<<"\nTelephone Numbers :\n";
for ( j = 0; e[i].telephone_numbers[j] > 0 && j < 5; j++ )

cout<<e[i].telephone_numbers[j];
}
getch ( ) ;
}
struct employee input ( )
{
struct employee temp ;
long int no;
int i ;
cout<<"Input the following -\n" ;
cout<<"Name : " ;
cin>>temp.name ;
cout<<"Address : ";
cin>>temp.address ;
cout<<"Telephone Numbers : ";
i = 0;
cin>>no;
while ( no > 0 && i < 4 )
{
temp.telephone_numbers[i] = no ;
i++ ;
cin>>no;
}
temp.telephone_numbers[i] = no ;
return ( temp ) ;
}

Example 30 : Array of Students as a function argument
#include <iostream.h>
#include <conio.h>
struct student
{
int roll_no ;
int physics_marks ;
int chemistry_marks ;
float average_marks ;
};
void main ()
{
void find_average ( struct student a[] ) ;
/* array of structure initialisation --

( average_marks are initially set to 0 ) */
struct student s[5] = { { 1, 50, 70, 0 },
{ 2, 67, 89, 0 },
{ 3, 78, 87, 0 },
{ 4, 56, 77, 0 },
{ 5, 49, 45, 0 } } ;
int i ;
clrscr ();
find_average ( s ) ;
cout<<"Student Information --\n\n" ;
for ( i = 0; i < 5; i++ )
{
cout<< "Student Roll No. : "<<s[i].roll_no<<endl ;
cout<< "Physics marks : "<<s[i].physics_marks<<endl;
cout<<"Chemistry marks : "<<s[i].chemistry_marks<<endl;
cout<<"Average marks : "<<s[i].average_marks<<endl;
}
getch ();
}
void find_average ( struct student a[] )
{
int i ;
for ( i = 0; i < 5; i++ )
{
a[i].average_marks = a[i].physics_marks + a[i].chemistry_marks ;
a[i].average_marks /= 2 ;
}
}
Example 31 : Program for Pointer to Structure
#include <iostream.h>
#include <conio.h>
void main ()
{
struct samplr
{
int x ;
int y ;
} a, *b ;
clrscr ( ) ;
a.x = 10 ;
a.y = 20 ;
b = &a;

cout<<"x : " <<(*b).x<<endl;
cout<<"y : "<<(*b).y<<endl ;
cout<<"x : " <<b->x<<endl;
cout<<"y : "<<b->y<<endl ;
getch ( ) ;
}

Example 32 : Array of pointers to structure
#include <iostream.h>
#include <conio.h>
struct sample
{
int a ;
char b ;
};
void main ()
{
/* Array of pointers to structure declaration */
struct sample *array[5] ;
/* structure declaration and initialisation */
struct sample s1 = { 1, 'A' } ;
struct sample s2 = { 2, 'B' } ;
struct sample s3 = { 3, 'C' } ;
struct sample s4 = { 4, 'D' } ;
struct sample s5 = { 5, 'E' } ;
int i ;
clrscr ();
array[0] = &s1;
/* pointer assignment */
array[1] = &s2;
array[2] = &s3;
array[3] = &s4;
array[4] = &s5;
for ( i = 0; i < 5; i++ ) /* accessing through pointers */
{
cout<<"Contents of structure ... "<<i+1 ;
cout<<"a : "<<(*array[i]).a<<endl ;
cout<<"b : "<<(*array[i]).b<<endl ;
}
getch ();
}

Example 33 : Summing an indirect array
#include <iostream.h>
float sum(float*[],int);
void print(float* [], int);
void main()
{
float a[8] = {1.1, 2.2, 3.3, 4.4, 5.5, 6.6, 7.7, 8.8};
float* p[8];
for (int i = 0; i < 8; i++)
p[i] = &a[i]; // p[i] points to a[i]
print(p, 8);
for (int n=0; n<8; n++)
cout << "sum(p," << n << ") = " << sum(p,n) << endl;
}
void print(float* a[], int n)
{
for (int i = 0; i < n; i++)
cout << *a[i] << " ";
cout << endl;
}
float sum(float* p[], int n)
{
float sum=0.0;
for (int i=0; i<n; i++)
sum += *p[i];
return sum;
}

Example 34 : Program for Use of Union
#include <iostream.h>
#include <conio.h>
void main ( )
{
union sample
/* union declaration */
{
int a ;
char b ;
float c ;
};
union sample s ; /* union variable declaration */
clrscr ( ) ;
/* stored as integer and retrieved as integer */

s.a = 10 ;
cout<<"a : "<<s.a ;
/* stored as character and retrieved as character */
s.b = 'x' ;
cout<<"b : "<<s.b<<endl ;
/* stored as float and retrieved as float */
s.c = 100.34 ;
cout<<"c : "<<s.c<<endl ;
/*stored as float and retrieved as integer-a wrong way*/
s.c = 1.567 ;
cout<<"a : "<<s.a <<endl;
getch ( ) ;
}

Example 35 : Program for Structure in an Union
#include <iostream.h>
#include <conio.h>
void main ( )
{
struct date
{
int day ;
int month ;
int year ;
};
union sample
{
char *sample_date_1 ;
struct date sample_date_2 ; /* structure within union */
};
union sample s ; /* union variable declaration */
clrscr ( ) ;
/* stored as string and retrieved as string */
s.sample_date_1 = "2 Nov 1999" ;
cout<<"Date : "<<s.sample_date_1;
/* stored as structure and retrieved as structure */
s.sample_date_2.day = 2 ;
s.sample_date_2.month = 11 ;
s.sample_date_2.year = 1999 ;
cout<<"Date : "<<s.sample_date_2.day;
cout<<" / "<<s.sample_date_2.month ;

cout<<"/"<<s.sample_date_2.year ;
getch () ;
}

Example 36 : Program for Structure containing Union
#include <iostream.h>
#include <conio.h>
union sample
{
int r1 ;
float r2 ;
};
struct triplet
{
int a ;
int b ;
int flag ;
/* 'flag' is used to indicate the type */
union sample c ; /* of value stored in union 'c' */
};
void main ( )
{
void find_divison ( struct triplet X[ ] ) ;
struct triplet X[5] ;
int i ;
clrscr () ;
cout<<"Input numbers :\n";
for ( i = 0; i < 5; i++ )
{
cin>>X[i].a;
cin>>X[i].b;
}
find_divison ( X ) ;
/* printing the result in correct format 'int' or 'float' */
for ( i = 0; i < 5; i++ )
{
cout<<"\nThe result of divison of "<<X[i].a<<"&"<<X[i].b<<" :
";
if ( X[i].flag == 0 )
cout<<X[i].c.r1;
else
cout<<X[i].c.r2;
}
getch ( ) ;

}
void find_divison ( struct triplet X[] )
{
int i ;
for ( i = 0; i < 5; i++ )
{
int temp ;
if ( X[i].a < X[i].b ) /* Swap if 'a' is less than 'b' */
{
temp = X[i].a ;
X[i].a = X[i].b ;
X[i].b = temp ;
}
if ( ( X[i].a % X[i].b ) != 0 )
{
/* if the result of divison is 'float' */
X[i].flag = 1 ; /* flag = 1, indicates 'float' result */
X[i].c.r2 = (float) X[i].a / (float) X[i].b ;
}
else
{
/* if the result of divison is 'int' */
X[i].flag = 0 ; /* flag = 0, indicates 'int' result */
X[i].c.r1 = X[i].a / X[i].b ;
}
}
}