C Program to find Sum of Array Elements

Problem: If an array of integers is given find the sum of its elements. Calculate sum of array elements using pointer as argument.

Examples : 
array[] = {10, 20, 30, 40, 50}
Sum of Array: 150
10 + 20 + 30 + 40 + 50 = 150

array[] = {1, 2, 3, 4, 5}
Sum of Array: 15
1 + 2 + 3 + 4 + 5 = 15

Solution:
  1. Create a static array of some fixed size, along with element declaration
  2. Build a function with a single argument, in which we will pass array argument
  3. Inside this function, all the elements of the array are accessed one-by-one, adding to return the sum
  4. Return sum to the called function and print it.

C program to find sum of array elements

/* Aim: C program to find the sum of all elements. */ 

#include<stdio.h>

int main()
{

	int array[100];
	int sum=0,size,i;

	int addnum(int *ptr);

	printf("\n Enter the size of array:- ");
	scanf("%d",&size);
    
	printf("\n Enter array elements:- ");
    
	for(i=0;i<size;i++)
		scanf("%d",&array[i]);

	for(i = 0; i < 5; i++) 
		sum += array[i];

	printf("\n Sum of all array elements = %5d \n", sum);

	return 0;
}

/* Output of above code:-

 Enter the size of array:- 5                                                                               
                                                                                                           
 Enter array elements:- 10 11 12 13 14                                                                     
 
 Sum of all array elements =    60

*/

C program to find sum of array elements using pointers and function

/* Aim: C program to find the sum of all elements of an array using  pointer as argument to function */ 

#include<stdio.h>

int main()
{

	static int array[100];
	int sum,size,i;

	int addnum(int *ptr);

	printf("\n Enter the size of array:- ");
	scanf("%d",&size);
    
	printf("\n Enter array elements:- ");
    
	for(i=0;i<size;i++)
		scanf("%d",&array[i]);

	sum = addnum(array);

	printf("\n Sum of all array elements = %5d \n", sum);

	return 0;
}

// Function to add array elements using pointer
int addnum(int *ptr)
{

	int i, sum = 0;

	for(i = 0; i < 5; i++) 
		sum += *(ptr + i);

	return(sum);

}

/* Output of above code:-

 Enter the size of array:- 5                                                                               
                                                                                                           
 Enter array elements:- 10 11 12 13 14                                                                     
 
 Sum of all array elements =    60

*/

C program to calculate sum of array elements using dynamic memory allocation

/* Aim: C program to read N integers and store them in an array A. Find the sum of all these elements using pointer. */ 

#include<stdio.h>
#include<malloc.h>

int main()
{
	int i, n, sum = 0;
	int *a; 
 
	printf("\n Enter the size of array:- ");
	scanf(" %d", &n); 

	a = (int *) malloc(n * sizeof(int));

	printf("\n Enter Elements:- ");

	for (i = 0; i < n; i++) 
		scanf(" %d", a + i);

	for (i = 0; i < n; i++)
		sum = sum + *(a + i);

	printf("\n Sum of all elements in array = %d \n", sum);

	return 0;

}

/* Output of above code:-

Enter the size of array:- 5

Enter array elements:-
10
20
30
40
50

Sum of all elements in array = 150

*/