C Program to Find the Sum of Elements in an Array

Introduction

Finding the sum of elements in an array is a common task in programming. This guide will show you how to write a C program to calculate the sum of all elements in an array provided by the user.

Problem Statement

Create a C program that:

• Takes the size of the array as input from the user.
• Takes the elements of the array as input.
• Calculates the sum of all elements in the array.
• Displays the sum.

Example:

• Input: Array size = 5, Elements = [1, 2, 3, 4, 5]
• Output: Sum = 15

Solution Steps

1. Include the Standard Input-Output Library: Use #include <stdio.h> to include the standard input-output library, which is necessary for using printf and scanf functions.
2. Write the Main Function: Define the main function, which is the entry point of every C program.
3. Declare Variables: Declare variables to store the array size, the array elements, and the sum of the elements.
4. Input the Array Size: Use scanf to take input from the user for the size of the array.
5. Input the Array Elements: Use a loop to take input from the user for the elements of the array.
6. Calculate the Sum: Use a loop to iterate through the array and calculate the sum of the elements.
7. Display the Sum: Use printf to display the sum of the elements.

C Program

#include <stdio.h>

/**
 * C Program to Find the Sum of Elements in an Array
 * Author: https://www.javaguides.net/
 */
int main() {
    // Step 1: Declare variables to hold the array size, elements, and sum
    int n, sum = 0;

    // Step 2: Prompt the user to enter the size of the array
    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    // Step 3: Declare an array to hold the elements
    int arr[n];

    // Step 4: Input the array elements
    printf("Enter %d elements:\n", n);
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    // Step 5: Calculate the sum of the array elements
    for (int i = 0; i < n; i++) {
        sum += arr[i];
    }

    // Step 6: Display the sum of the elements
    printf("Sum of the elements: %d\n", sum);

    return 0;  // Step 7: Return 0 to indicate successful execution
}

Explanation

Step 1: Declare Variables

• The variable n is declared to store the size of the array. sum is initialized to 0 and will store the sum of the array elements.

Step 2: Input the Array Size

• The program prompts the user to enter the size of the array using printf. The scanf function then reads the input and stores it in the variable n.

Step 3: Declare the Array

• The program declares an array arr of size n to hold the elements provided by the user.

Step 4: Input the Array Elements

• The program uses a for loop to take input for each element of the array. The loop iterates from 0 to n-1, reading the elements using scanf.

Step 5: Calculate the Sum of the Array Elements

• The program uses another for loop to iterate through the array and calculate the sum of the elements. The loop iterates from 0 to n-1, adding each element to the sum variable.

Step 6: Display the Sum

• The program displays the sum of the elements using the printf function.

Step 7: Return 0

• The return 0; statement indicates that the program executed successfully.

Output Example

Example:

Enter the number of elements in the array: 5
Enter 5 elements:
1
2
3
4
5
Sum of the elements: 15

Conclusion

This C program demonstrates how to find the sum of elements in an array. It covers basic concepts such as arrays, loops, and arithmetic operations, making it a useful example for beginners learning C programming.