C Program to Swap Two Numbers Using Pointers

In the world of C programming, pointers stand as powerful entities that facilitate direct memory manipulation. Pointers hold memory addresses and allow us to access and modify data indirectly, offering flexibility and efficiency in programming. Let’s write a simple C program that swaps the values of two numbers using pointers

C Pointer Basics

A pointer in C is a variable that holds the memory address of another variable. By dereferencing a pointer, we can access or modify the value stored at that address. This functionality forms the core of various operations, including swapping two variables without using a temporary variable.

C Program to Swap Two Numbers Using Pointers

// C Program to Swap Two Numbers Using Pointers
#include <stdio.h>

// Function to swap two numbers using pointers
void swapNumbers(int *ptr1, int *ptr2) {
    *ptr1 = *ptr1 + *ptr2;
    *ptr2 = *ptr1 - *ptr2;
    *ptr1 = *ptr1 - *ptr2;
}

void main() {
    int num1, num2;

    // Input for two numbers
    printf("Enter first number: ");
    scanf("%d", &num1);
    printf("Enter second number: ");
    scanf("%d", &num2);

    // Displaying original numbers
    printf("\nOriginal numbers: num 1 = %d, num 2 = %d\n", num1, num2);

    // Calling the function to swap numbers using pointers
    swapNumbers(&num1, &num2);

    // Displaying swapped numbers
    printf("Swapped numbers: num 1 = %d, num 2 = %d\n", num1, num2);

}

Output

C Program to Swap Two Numbers Using Pointers – Explanation

1. swapNumbers Function:
   • This function takes two integer pointers ptr1 and ptr2 as parameters.
   • Using pointer dereferencing (*ptr1 and *ptr2), it performs arithmetic operations to swap the values of the numbers without using a temporary variable.
2. main() Function:
   • Declares variables num1 and num2 to store user-input values.
   • Prompts the user to input two numbers.
   • Displays the original numbers using printf().
   • Calls the swapNumbers() function by passing the addresses of num1 and num2.
   • Displays the swapped numbers using printf().

See Also

• C Program to Print Sum of Even and Odd Numbers
• C Code for Addition of Two Numbers
• Binary Search in C
• C Program to Find Area of Rectangle Using Function