Program 52 - CSU1128 - CSE 2026 - Shoolini University

Program to demonstrate the pointers

Explanation

The program demonstrates the use of pointers by allowing the user to enter a value for a variable and then modifying that value using a pointer.

Header

The code begins with including the standard input-output header file using #include <stdio.h>.

Variable Declaration

The main() function is defined, and an integer variable and a pointer to that variable are declared:

int d;: Variable to hold the value entered by the user.
int *m = &d;: Pointer to hold the address of d and initialized with the address of d.

Program Description

The program prints a description message for the user to understand its functionality.

User Input

The user is prompted to enter the value of d:

printf("Enter the value of X: ");: Prompts the user to enter the value of d.
scanf("%d", &d);: Reads the value entered by the user and stores it in d.

Pointer Demonstration

The program demonstrates the use of pointers by printing the values and addresses:

printf("d = %d\n", d);: Prints the value of d.
printf("&d = %p\n", &d);: Prints the memory address of d.
printf("m = %p\n", m);: Prints the value of the pointer m (address of d).
printf("*m = %d\n", *m);: Prints the value stored at the memory address pointed to by m.

Modify Value Using Pointer

The program modifies the value of d using the pointer m:

printf("Enter the new value of *m pointer to modify the value of X: ");: Prompts the user to enter a new value using the pointer.
scanf("%d", &*m);: Reads the new value and stores it in the memory address pointed to by m.

Output Modified Value

The program prints the modified value of d:

printf("d = %d\n", d);: Prints the modified value of d.

Program End

The program ends with return 0; to indicate successful execution.

Code

                    
/*
 * -----------------------------------------------------------
 * Logic Building with Computer Programming (CSU1128)
 * Instructor: Dr. Pankaj Vaidya | Author: Divya Mohan
 * 
 * This code is a part of the educational initiative by dmj.one
 * with aim of empowering and inspiring learners in the field of
 * Computer Science and Engineering through the respective courses.
 * 
 * (c) 2022, Divya Mohan for dmj.one. All rights reserved.
 * -----------------------------------------------------------
 */

#include <stdio.h>

int main()
{
    printf("\n\n Program to demonstrate the pointers. \n\n");
    
    // Declare an integer variable and a pointer to that variable
    int d;
    int *m = &d;
    
    // Get input for the value of X
    printf("Enter the value of X: ");
    scanf("%d", &d);
    
    // Print the value of d and the memory address of d
    printf("d = %d\n", d);
    printf("&d = %p\n", &d);
    
    // Print the value of m and the value stored at the memory address pointed to by m
    printf("m = %p\n", m);
    printf("*m = %d\n", *m);
    
    // Modify the value of d using the pointer
    
    printf("Enter the new value of *m pointer to modify the value of X: ");
    scanf("%d", &*m);
    
    // Print the modified value of d
    printf("d = %d\n", d);
    
    return 0;
}

Output

Program to demonstrate the pointers.

Enter the value of X: 6
d = 6
&d = 0x7ffc22169b88
m = 0x7ffc22169b88
*m = 6
Enter the new value of *m pointer to modify the value of X: 3
d = 3