Write a program using pointers to compute the sum of all elements stored in an array.

Program :

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#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]);      ptr = numArray; /* a=&a[0] */      for (i = 0; i < 10; i++) {       sum = sum + *ptr;       ptr++;    }      printf("The sum of array elements : %d", sum); }

Output :

1 2	Enter 10 elements : 11 12 13 14 15 16 17 18 19 20 The sum of array elements is 155

Explanation of Program :

Accept the 10 elements from the user in the array.

1 2	for (i = 0; i < 10; i++) scanf("%d", &numArray[i]);

We are storing the address of the array into the pointer.

1	ptr = numArray; /* a=&a[0] */

Now in the for loop we are fetching the value from the location pointer by pointer variable. Using De-referencing pointer we are able to get the value at address.

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

Suppose we have 2000 as starting address of the array. Then in the first loop we are fetching the value at 2000. i.e

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sum = sum + (value at 2000)     = 0   + 11     = 11

In the Second iteration we will have following calculation –

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sum = sum + (value at 2002)     = 11  + 12     = 23