write A programme to print the sum of all natural number from 1 to n using while loop

  //write A programme to print all natural number from 1 to n using while loop

#include "stdio.h"

int main (){

    int n,i,sum;

    printf ("Enter the last number of the series :\n");

    scanf ("%i",&n);

    i=1;

     while (i<=n){

        sum=sum+i;

        i++;

     }

     printf ("The sum of the series is %i",sum);

     return 0;

}

output :

Enter the last number of the series : 10 The sum of the series is 55