C Program to Add Two Numbers using Pointers

In this article, we will learn how we can add two numbers using pointers in C programming.

The program takes two integer inputs from the user and prints their sum as a result.

Sample Input:

Enter the first number: 10
Enter the second number: 20

Output:

The sum of the two numbers is: 30

Before we dive into the explanation of the actual program, let’s first have a look at pointers in C language.

In C programming language, a pointer is used to store the memory address of a variable. It is declared by placing an asterisk symbol(*) before the variable name, eg. *myVar.

To store the address of a variable in a pointer, we place an ampersand(&) symbol before the variable. For example:

int a = 10, *myVar;

// Store the address of variable a in pointer myVar
myVar = &a;

In the above example, the pointer myVar will store the memory address of the variable a.

Now, if you want to access the value that the pointer myVar is pointing to, you can place an asterisk(*) symbol before it.

For example, if you try to print the value of myVar and *myVar, you will find that myVar prints the memory address of the variable a whereas *myVar prints the value of the variable a.

int a = 10, *myVar;

// Store the address of variable a in pointer myVar
myVar = &a;

printf("%d ", myVar);  // 6487572
printf("%d", *myVar);  // 10

We can use the above concept to add two numbers using pointers.

You need to simply follow the below steps to add two numbers using C pointers:

• Create two integer variables a & b to take input from the user. Also create two pointer variables *p and *q which will hold the addresses of a and b.
• Take the inputs from the user using the scanf() function and store them in variables a and b.
• Store the memory address of the variable a in pointer p and the memory address of the variable b in pointer q.
• Get the sum of the two numbers by dereferencing pointers p and q i.e. *p + *q and store the result in the sum variable.
• Print the result stored in the sum variable using the printf() function.

Here is the implementation of the above steps:

// C program to add two numbers using pointers

#include <stdio.h>

int main(){
    
    // Declare the variables and pointers
    int a, b, *p, *q, sum;
    
    // Get the first number
    printf("Enter the first number: ");
    scanf("%d", &a);
    
    // Get the second number
    printf("Enter the second number: ");
    scanf("%d", &b);
    
    p = &a;  // Store address of a in pointer p
    q = &b;  // Store address of b in pointer q
    
    // Get the sum by dereferencing pointers p & q
    sum = *p + *q;
    
    // Print the result
    printf("The sum of the two numbers is: %d", sum);
    
    return 0;
}

Output:

Enter the first number: 10
Enter the second number: 20
The sum of the two numbers is: 30

Thanks for reading.