C Program to Find the Sum of Array Elements Using Pointers

This C program demonstrates how to calculate the sum of all elements in an array using pointers. The program defines a function called `sum_of_array_elements` that takes an array and its size as arguments, then uses a pointer to traverse the array and compute the sum.

Code Implementation

#include <stdio.h>

// Function to calculate the sum of array elements using pointers
int sum_of_array_elements(int arr[], int size) {
    int sum = 0;
    int *ptr = arr;  // Initialize pointer to the first element of the array

    // Traverse the array using the pointer and calculate the sum
    for (int i = 0; i < size; i++) {
        sum += *ptr;  // Dereference the pointer to access the current element
        ptr++;  // Increment the pointer to point to the next element
    }

    return sum;
}

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    int size = sizeof(arr) / sizeof(arr[0]);

    printf("Array elements: ");
    for (int i = 0; i < size; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");

    int sum = sum_of_array_elements(arr, size);
    printf("Sum of array elements: %d\n", sum);

    return 0;
}

Explanation

The `sum_of_array_elements` function takes an array `arr` and its size `size` as arguments. It initializes a pointer `ptr` to the first element of the array using `int *ptr = arr;`. Then, it uses a `for` loop to traverse the array, dereferencing the pointer to access each element and adding it to the sum. The pointer is incremented using `ptr++` to point to the next element in each iteration.

In the `main` function, we define an example array `arr` and calculate its size using `sizeof(arr) / sizeof(arr[0])`. We then call the `sum_of_array_elements` function, passing the array and its size as arguments, and print the result.

Output

When you run this program, it will output the sum of the array elements:

Array elements: 1 2 3 4 5
Sum of array elements: 15

Tips and Variations

* To make the program more flexible, you can ask the user to input the array size and elements. * You can also modify the program to calculate the sum of elements in a 2D array or a matrix. * To improve performance, consider using a more efficient algorithm, such as the divide-and-conquer approach, for large arrays.