Pointers in C++

1. Lecture 7
ChaaND Sheikh

2. Pointers.

3. //Demonstration.
#include<conio.h>
Every Block is
#include<iostream.h>
a memory cell
void main()
{
Cell no’s / Address
int x ;
float y;
x = 10;
Memory
4001
4002
4003
4004
4005
4006
4007
4008
4009
10
x
y
4007
y = 20.0;
}
cout<<“Value’s of x and y = “<<x<<y;
getch();
4007
20.0
4002

4. • Pointers deals with memory address, using pointers we
can access memory directly. storing pointer type entity
we need special type variables.
•
data-type * Variable_name;
Type of data
stored in the
address of
the variable.
Indirection
operator

5. &
*
Address of (Reference) Operator.
Value At Address (Indirection) operator.
void main()
20.0
Value at Address.
{
int *int_ptr;
10
float *float_ptr;
Address
4002
4007
int x = 10 ;
x
y
Name od address
float y = 20.0;
cout<<“Value’s of x and y = “<<x<<“ “<<y;
int_ptr = &x;
float_ptr = &y;
cout<<"int_ptr = "<<int_ptr;
cout<<"n float_ptr = "<<float_ptr;
cout<<"n value in int_pointer = "<< *int_ptr;
cout<<"n value in float_ptr = "<< *float_ptr;
getch(); }

6. &
Address of (Reference) Operator.
*
Value At Address (Indirection) operator.
// Demonstration.
#include <iostream.h>
#include<conio.h>
void main ()
{
int variable ;
int *mypointer;
mypointer = &variable;
*mypointer = 50;
50
3722
variable
Address of variable = mypointer
50 = value at address
cout << "value in variable is " <<variable<<endl;
getch();
}
Value in variable is 50

7. //Demonstration
& Address of (Reference) Operator.
#include <iostream.h>
* Value At Address (Indirection) operator.
#include<conio.h>
main ()
{
10
5888
2554
int x=10;
int *y;
2554
5888
6550
int **z;
**z
x
*y
cout<<"Value of x = "<<x;
cout<<"nAdd of x = "<<&x;
Value of x = 10
cout<<"nValue of x = "<<*(&x);
Add of x = 2554
y=&x;
cout<<"nAdd of y = "<<&y;
Value of x = 10
cout<<"nAdd in y = "<<y;
Add of y = 5888
z=&y;
cout<<"nAdd of z = "<<&z;
Add in y = 2554
cout<<"nAdd in z = "<<z;
getch();
Add of y = 6550
}
Add in z = 5888

8. //Demonstration
& Address of (Reference) Operator.
#include <iostream.h>
* Value At Address (Indirection) operator.
#include<conio.h>
main ()
{
10
5888
2554
int x=10;
2554
5888
6550
int *y;
**z
x
*y
int **z;
cout<<"Value of x = "<<x;
cout<<"nAdd of x = "<<&x;
Value of x = 10
y=&x;
Add of x = 2554
cout<<“Accessing x via ptr y = ”<<*y;
z=&y;
x via prt y = 10
cout<<“Accessing x via ptr z ”<<**z;
x via prt z = 10
getch();
}

9. &
Address of (Reference) Operator.
*
Value At Address (Indirection) operator.
1. *& variable = variable
2. *(&)variable = *&variable
Example 1 :
int x =10;
cout<<*&x;
10
cout<<*(&)x;
Example 2 :
int x = 10;
int * p;
p = &x;
cout<<* p;
10