This is an PPT is an PPt of C++ Programming Language. This includes topics such as " Pointer Basics,Constant Pointers & Pointer to Constant"

1. BIRLA INSTITUTE OF
TECHNOLOGY
TOPIC :- POINTERS BASICS, CONSTANT
POINTERS AND POINTERS TO CONSTANT
DIVYANSH
PARMARTHI
MCA/25016/18
SHRADDHA

2. POINTERS
• A pointer is a variable that points a address of a variable.
• A pointer is declared using the * operator before an identifier.

3.  Declaration of Pointer variables :
type *pointer_name;
where type is the type of data pointed to
For example :- int *numberPointer;

4. ADDRESS (&) OPERATOR
 Pointer address operator is denoted by ‘&’ symbol
 The & is a unary operator that returns the memory address of its
operand.
Example :
&n - It gives an address on variable n

5. DEREFERENCING OPERATOR (*)
 We can access to the value stored in the variable pointed to by
using the dereferencing operator (*)
Syntax: *PointerVariable
Example:
int V = 101;
int *P = &V;

6. POINTERS TO POINTERS
 A pointer to a pointer is a chain of pointers.
 In pointer to a pointer, the first pointer contains the address of the
second pointer, which points to the location that contains the actual
value.
Pointer Pointer Variable
Address Address Value

7. Declaration of pointer to a pointer :
int **ptr;
For example :
// local declaration
int a;
int *p;
int **q;
// Statment
a=58;
p=&a;
q=&p;

8. cout << a << “ “ <<endl;
cout << *p << “ “ <<endl;
cout<< **q << “ “ <<endl;
OUTPUT
58
58
58

9. POINTERS AS PARAMETERS
 To make changes to a variable that exist after a function ends, we
pass the address of the variable to the function
For example :
#include<iostream.h>
void Indirectswap(char *ptr1, char *ptr2)
{
char c = *ptr1;
*ptr1 = *ptr2;
*ptr2 = c;
}

10. int main()
{
char a = ‘y’;
char b = ‘n’;
Indirectswap(&a,&b);
cout<< a << “and”<< b << endl;
return 0;
}
OUTPUT
n and y

11. CONSTANT POINTERS AND
POINTERS TO CONSTANT
BY :-
SHRADDHA
MALVIYA

12. Constant pointer
 Constant pointer cannot be modified.
 Modification in integer to which it points to it is allowed.
 Syntax:
int n1=20;
int *const ptr=&n1; //Declare constant

13. Example of constant pointer

14. Output

15. Pointer to constant
 Pointer to constant object is called as pointer to constant object.
Syntax:
int n=30;
const int *ptr=&n;
“const int” means integer constant.
We cannot change value of integer.
We can change address of such pointer so that it will point to new
memory allocation

16. Example of pointer to constant

17. Output

18. Difference
Constant pointer Pointer to constant
Pointer can be incremented. Pointer is not incremented.
Constant pointer is pointing to data object. Pointer is pointing to constant data object.t
Declaration :int * const ptr; Declaration: const int *ptr;

19. THANK
YOU