C program to find sum of N numbers using function

C program to find sum of n numbers using function – To get the sum, the program contains a user defined sum function that receives a number as an argument, sum all numbers e.g. 1+2+3.. and returns the result.

e.g. if you want to get sum of numbers from 1 to 5 i.e. 1+2+3+4+5, then you need to enter number 5. the function will sum numbers from 1 to 5.

Test case:

Enter number 3

sum : 6

Program description:

Use a for loop in C program below and loop through the number from 1 to given number and sum all using statement sum += i. It can also be written as sum = sum +i;

C code to find sum of n numbers using function

/*
* C program to find sum of n numbers using function
*/

#include<stdio.h>

/*Write sum function that recieves the number
* as an argument up to which you want to sum.
* Return the total sum
*/
int sum(int num){

	int i;
	int sum =0;

	//Loop through from 1 to num e.g.
	//if number is 3 so index will start from
	// 1 to 3 and sum will be as = 1+2+3 = 6
	for(i=1; i<=num; ++i){
		sum += i; // Also, this can be written as sum = sum +i;
	}
	return sum;
}

/*
* Test sum of n numbers
*/

int main(){

	int num =0;
	int result =0;

	printf("Enter number ");

	//Read the number up to which you want sum
	scanf("%d", &num);

	//call sum function that will return sum

	result = sum(num);

	printf("sum : %d ",result);

	return 0;
}

Output:
Enter number 3
sum : 6