Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
How to calculate sum of array elements using pointers in C language?
Pointer is a variable which stores the address of other variable.
Consider the following statement −
int qty = 179;
Declaring a pointer
The syntax for declaring a pointer is as follows −
int *p;
Here, ‘p’ is a pointer variable which holds the address of other variable.
Initialization of a pointer
Address operator (&) is used to initialize a pointer variable.
For example,
int qty = 175; int *p; p= &qty;
Array of Pointers
It is collection of addresses (or) collection of pointers.
Declaration
Following is the declaration for array of pointers −
datatype *pointername [size];
For example,
int *p[5];
It represents an array of pointers that can hold five integer element addresses.
Initialization
‘&’ is used for initialization
For example,
int a[3] = {10,20,30};
int *p[3], i;
for (i=0; i<3; i++) (or) for (i=0; i<3,i++)
p[i] = &a[i];
p[i] = a+i;Accessing
Indirection operator (*) is used for accessing.
For example,
for (i=0, i<3; i++)
printf ("%d", *p[i]);Program
Following is the C program to calculate the sum of the array elements by using pointers −
//sum of array elements using pointers
#include <stdio.h>
#include <malloc.h>
void main(){
int i, n, sum = 0;
int *ptr;
printf("Enter size of array :
");
scanf("%d", &n);
ptr = (int *) malloc(n * sizeof(int));
printf("Enter elements in the List
");
for (i = 0; i < n; i++){
scanf("%d", ptr + i);
}
//calculate sum of elements
for (i = 0; i < n; i++){
sum = sum + *(ptr + i);
}
printf("Sum of all elements in an array is = %d
", sum);
return 0;
}Output
When the above program is executed, it produces the following result −
Enter size of array: 5 Enter elements in the List 12 13 14 15 16 Sum of all elements in an array is = 70
16K+ Views
