Pointer Simple Example Program with Reference operator (&) and Dereference operator (*)

Pointer Definition

The pointer is a programming language data type whose value refers directly to (or "points to") another value stored elsewhere in the computer memory using its address.

Accessing The Address:

& - Locate the Variable Address

&variable

ponter_variable = &variable;

Declaring Pointer Variables

  • * and variable name 
  • pointer variable points to a variable of type data_type 

Syntax:

data_type *pt_name;

Example:

int *p;

float *x;

Initialization Of Pointer Variable:

pointer_vaibale = &variable;

Reference operator ("&")

The reference operator noted by ampersand ("&"), is also a unary operator in c languages that uses for assign address of the variables. It returns the pointer address of the variable. This is called "referencing" operater. 

Dereference operator ("*")

The dereference operator or indirection operator, noted by asterisk ("*"), is also a unary operator in c languages that uses for pointer variables. It operates on a pointer variable, and returns l-value equivalent to the value at the pointer address. This is called "dereferencing" the pointer. 

1).Normal Variable

int var;

2). Pointer Variable Declaration for Integer Data Type 

int *pt;

3). now var == 0

var = 0;

4). & takes the address of var , Here now pt == &var, so *pt == var

pt = &var;

5). Assign Values using dereference operator

*pt = 1; 

its equivalent to var = 1, since *pt == var, now *pt == 1 and *pt == var, so var == 1

Pointer Simple Example Program for understand Reference operator (&) and Dereference operator (*)

/*##Pointer Example Program with Reference operator (&) and Dereference operator (*)*/
/*##Simple Pointer Programs,Reference operator,Dereference operator*/

// Header Files
#include <iostream>
#include<conio.h>

using namespace std;

int main() {

   //Pointer Variable Declaration for Integer Data Type 
   int* pt;
   int var;

   cout << "C++ Pointer Example for Reference operator (&) and Dereference operator (*)\n";

   var = 1;

   cout << "Address of var 			:" << &var << "\n";
   cout << "Value   of var 			:" << var << "\n\n";

   //& takes the address of var , Here now pt == &var, so *pt == var
   pt = &var;

   cout << "Address of Pointer pt 	:" << pt << "\n";
   cout << "Content of Pointer pt 	:" << *pt << "\n\n";

   var = 2;

   cout << "Address of Pointer pt 	:" << pt << "\n";
   cout << "Content of Pointer pt 	:" << *pt << "\n\n";

   //Assign Values using dereference operator
   *pt = 3;

   cout << "Address of var			:" << &var << "\n";
   cout << "Value   of var			:" << var << "\n\n";

   getch();
   return 0;

}

Sample Output:

C++ Pointer Example for Reference operator (&) and Dereference operator (*)

Address of var   :1565276140
Value  of var   :1

Address of Pointer pt:1565276140
Content of Pointer pt:1

Address of Pointer pt:1565276140
Content of Pointer pt :2

Address of var  :1565276140
Value  of var  :3

(output may vary based on system memory)