Program to calculate sum of array in C

This program should give an insight of how to parse (read) array. We shall use a loop and sum up all values of the array.

Algorithm

Let's first see what should be the step-by-step procedure of this program −

START
   Step 1 → Take an array A and define its values
   Step 2 → Loop for each value of A
   Step 3 → Add each element to 'sum' variable
   Step 4 → After the loop finishes, display 'sum'
STOP

Pseudocode

Let's now see the pseudocode of this algorithm −

procedure sum_array(A)

   Declare sum as integer
   FOR EACH value in A DO
      sum ← sum + A[n]
   END FOR
   Display sum

end procedure

Implementation

This pseudocode can now be implemented in the C program as follows −

#include <stdio.h>

int main() {
   int array[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
   int sum, loop;

   sum = 0;
   
   for(loop = 9; loop >= 0; loop--) {
      sum = sum + array[loop];      
   }

   printf("Sum of array is %d.", sum);   

   return 0;
}

The output should look like this −

Sum of array is 45.