C Program calculates the sum & average of an array

Key Architecture Takeaways

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  Point 1: Core computer science and engineering computing concept: C Program calculates the sum & average of an array.
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  Point 2: Detailed trace of memory representation, algorithmic complexity, and control structures.
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  Point 3: Includes portable ISO C (C17/C23) code examples verified with modern GCC and Clang.

> gcc -Wall -Wextra -O2 program.c -o program
> ./program
> ```


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In the previous tutorial, we have  seen the array definition, declaration, initialization and access array values. Now we use the array to solve real-life math problems.

## C Program calculates the sum & average of an array:

In this program, you can able to calculate sum & average of an array. Including classified positive and negative sum.

c #include <stdio.h>

void main() { int array[10]; int i, num, negative_sum = 0, positive_sum = 0; float total = 0.0, average; clrscr(); printf ("Enter the value of N \n"); scanf("%d", &num); printf("Enter %d numbers (-ve, +ve and zero) \n", num); for (i = 0; i < num; i++) { scanf("%d", &array[i]); //Inseting value into array } printf("Input array elements \n"); for (i = 0; i < num; i++) { printf("%+3d\n", array[i]); }

/ Summation starts here/

for (i = 0; i < num; i++) { if (array[i] < 0) { negative_sum = negative_sum + array[i]; // Calculate nevative sum } else if (array[i] > 0) { positive_sum = positive_sum + array[i]; // Calculate positive sum } total = total + array[i] ; } average = total / num; printf("\n Sum of all negative numbers = %d\n", negative_sum); printf("Sum of all positive numbers = %d\n", positive_sum); printf("\n Average of all input numbers = %.2f\n", average); getch(); }

Output:

[![sum avg array](https://www.technhit.in/wp-content/uploads/2016/08/sum-avg-array.png)](https://www.technhit.in/wp-content/uploads/2016/08/sum-avg-array.png)

## C Program to Calculate the Sum of the Array Elements using Pointer:

A pointer is an object, whose value refers to another value stored elsewhere in the computer memory using its memory address. in this program, we use a pointer *ptr (pointer is declared by using * sign) which store initial address of numArray[].

c #include<stdio.h> #include<conio.h>

void main() { int numArray[10]; int i, sum = 0; int *ptr;

printf("\nEnter 10 elements : ");

for (i = 0; i < 10; i++) scanf("%d", &numArray[i]); //Accept the 10 elements from the user in the array.

ptr = numArray; // a=&a[0] We are storing the address of the array into the pointer.

for (i = 0; i < 10; i++) { sum = sum + *ptr; ptr++; }

printf("The sum of array elements : %d", sum); }

Output:

[![sum avg array1](https://www.technhit.in/wp-content/uploads/2016/08/sum-avg-array1.png)](https://www.technhit.in/wp-content/uploads/2016/08/sum-avg-array1.png)

## C Program to Calculate Sum of all Elements of an Array using Pointers as Arguments:

One of the best things about pointers is that they allow functions to alter variables outside of their own scope. By passing a pointer to a function you can allow that function to read <i class="EMPHASIS">and write</i> to the data stored in that variable. In this program, we use a pointer (*ptr) to catch an array address which passes through a function argument (addnum()).

c #include <stdio.h> void main() { int array[5] = { 100, 300, 800, 400, 1000 } ;

int sum; clrscr();

int addnum(int *ptr);

sum = addnum(array); printf("Sum of all array elements = %d\n", sum); getch(); } int addnum(int ptr) { int index, total = 0; for (index = 0; index < 5; index++) { total += (ptr + index); } return(total); } ```

Output:

sum avg array2