The document discusses pointers in C++, including how to access addresses and contents using pointers, how to access array elements using indexes and pointers, and how pointers can be used to pass arguments to functions by reference or by pointer. It also provides examples of pointer usage and briefly describes bubble sort as a sorting algorithm.

1. Chapter: 10
Pointers
Lecture: 38 and 39
Date: 18.10.2012

2. Accessing Addresses
int main()
{ int IntVar1 = 25;
int IntVar2 = 11;
int* ptr; //pointer to integers
ptr = &IntVar1; //pointer points to IntVar1
cout << ptr << endl //print the address of IntVar1
ptr = &IntVar2
cout << ptr << endl //print the address of IntVar2
getch();
return 0; }

3. Accessing Contents
int main()
{ int IntVar1 = 25;
int IntVar2 = 11;
int* ptr; //pointer to integers
ptr = &IntVar1; //pointer points to IntVar1
cout << *ptr << endl //print the content of IntVar1
ptr = &IntVar2
cout << *ptr << endl //print the content of IntVar2
getch();
return 0; }

4. Array Accessing Using Index
int main()
{
int intarray[5] = { 31, 54, 77, 52, 93 };
for(int j=0; j<5; j++)
cout << intarray[j] << endl;
getch();
return 0;
}

5. Array Accessing Using Pointers
int main()
{
int intarray[5] = { 31, 54, 77, 52, 93 };
for(int j=0; j<5; j++)
cout << *( intarray + j ) << endl;
getch();
return 0;
}

6. Counting by Integers - Arrays

7. Passing Arguments to Functions
 Arguments can be passed to functions in three
different ways: (i) by value, (ii) by reference, and (iii) by
pointers
 A function can change the values in a calling function if
the arguments are passed by a reference or by a pointer.

8. Pass-by-Reference
void centimize(double& );
int main()
{ double var = 2.5;
centimize(var);
cout << var << endl;
getch(); return 0; }
void centimize(double& v)
{ v = v * 100; }

9. Pass-by-Pointer
void centimize(double* );
int main()
{ double var = 2.5;
centimize(&var);
cout << var << endl;
getch(); return 0; }
void centimize(double* ptrd)
{ *ptrd = *ptrd * 100; }

10. Pointer Passed to Function

11. Passing Arrays to Function
const int MAX = 5;
void centimize(double*);
int main()
{ double varray[MAX] = { 10.0, 43.1, 95.9, 59.7, 87.3 };
centimize(varray);
for(int j=0; j<MAX; j++)
cout << varray[j] << endl;
getch(); return 0; }
void centimize(double* ptrd)
{ for(int j=0; j<MAX; j++)
*ptrd++ = *ptrd * 2.54; } //*ptrd++ = *(ptrd++)

12. Pointer Passed to Function

13. Assignment # 02
(i) Write a note on sorting with an example.
(ii) What is bubble sort? Write a program implementing
bubble sort using pointers.

14. Assignment # 02
(i) Write a note on sorting with an example
(ii) What is bubble sort? Write a program implementing
bubble sort using pointers.
Viva voce for the first and second assignment is
scheduled to be conducted on 24th October.