Sum of N Numbers

This code takes a user-defined number ‘n’, calculates the sum of all natural numbers from 0 to ‘n’, and then prints the result. It uses a for loop to iterate through the numbers and an accumulator variable sum to keep track of the total.

#include<stdio.h>
main()
{
  int i,n,sum=0;
  printf("Enter a number\n");
  scanf("%d",&n);
  for(i=0;i<=n;i++)
  {
    sum=sum+i;
  }
  printf("%d\n",sum);
}

Enter a number
6
21

Explanation:

This C program calculates the sum of all natural numbers from 0 to a user-defined number ‘n’. Here’s a step-by-step explanation of the code:

Header File:

• The program includes the standard C library header <stdio.h> for input and output operations.

Main Function:

• The main function is the entry point of the program.

Variable Declaration:

Two variables are declared:

• i (int): It is used as a loop counter to iterate through the natural numbers.
• n (int): This variable will store the user input for the upper limit ‘n’.
• sum (int): This variable will store the sum of the natural numbers.

User Input:

• The program prompts the user to enter a number by displaying the message “Enter a number”.
• The user’s input is read and stored in the variable n using scanf.

For Loop:

• The for loop is used to iterate from 0 to ‘n’, including both 0 and ‘n’.
• i is initialized to 0, and the loop continues as long as i is less than or equal to n.
• In each iteration of the loop, the value of i is added to the sum.

Accumulating Sum:

• Within the loop, the value of i is added to the sum. This accumulates the sum of natural numbers from 0 to ‘n’.

Print Result:

• After the loop completes, the program uses printf to display the calculated sum. The format specifier %d is used to print the integer value of sum.

End of Program:

• Once the result is displayed, the program reaches the end of the main function and terminates.