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C program to sum of natural numbers from1 to n language|5 ways
In this tutorial, we will discuss the concept of C program to the sum of Natural number from 1 to n – (n is entered number)
In this post, we are going to learn how to find the sum of natural numbers in C language in different 5 ways

Sum of natural numbers from1 to n-using for loop
Program 1
#include <stdio.h>
#include <stdlib.h>
int main()
{
int sum=0,num,i;
printf("Enter a natural number\n");
scanf("%d",&num);
for(i=1; i<=num; i++){
sum+=i; //sum=sum+i;
}
printf("Sum of natural numbers from 1 to %d: %d",num,sum);
getch();
return 0;
}
When the above code is executed it produces the following output
Enter a natural number 10 Sum of natural numbers from 1 to 10: 55
This program allows the user to enter a maximum number. and it displays sum of natural numbers from 1 to given number using for loop in C language
Sum of natural numbers from1 to n-using while loop
Program 2
#include <stdio.h>
#include <stdlib.h>
int main()
{
int sum=0,num,i;
printf("Enter a natural number\n");
scanf("%d",&num);
i=1;
while(i<=num){
sum+=i; //sum=sum+i;
i++;
}
printf("Sum of natural numbers 1 to %d: %d",num,sum);
getch();
return 0;
}
When the above code is executed it produces the following output
Enter a natural number 12 Sum of natural numbers 1 to 12: 78
This program allows the user to enter a maximum number. and it displays sum of natural numbers from 1 to given number using while loop in C language
Sum of natural numbers from1 to n-using do-while loop
Program 3
#include <stdio.h>
#include <stdlib.h>
int main()
{
int sum=0,num,i;
printf("Enter a natural number\n");
scanf("%d",&num);
i=1;
do{
sum+=i; //sum=sum+i;
i++;
} while(i<=num);
printf("Sum of natural numbers 1 to %d: %d",num,sum);
getch();
return 0;
}
When the above code is executed it produces the following output
Enter a natural number 100 Sum of natural numbers 1 to 100: 5050
This program allows the user to enter a maximum number. and it displays sum of natural numbers from 1 to given number using the do-while loop in C language
Sum of natural numbers from1 to n-using function
Program 4
#include <stdio.h>
#include <stdlib.h>
sumNatyralnum(int);//function prototype
int main()
{
int num,sum=0;
printf("Enter a natural number\n");
scanf("%d",&num);
sum=sumNatyralnum(num);//function call
getch();
printf("The sum of natural numbers 1 to %d : %d",num,sum);
return 0;
}
int sumNatyralnum(int n){//function definition
if(n==0)
{
return n;
}
else{
return (n*(n+1)/2);
}
}
When the above code is executed it produces the following output
Enter a natural number 20 The sum of natural numbers 1 to 20 : 210
This program allows the user to enter a maximum number. and it displays the addition of natural numbers from 1 to given number using the function in C language
Sum of natural numbers from1 to n-using recursive function
Program 5
#include <stdio.h>
#include <stdlib.h>
sumNaturalnum(int);
int main()
{
int num,sum=0;
printf("Enter a natural number\n");
scanf("%d",&num);
sum=sumNaturalnum(num);
printf("The sum of natural numbers 1 to %d : %d",num,sum);
getch();
return 0;
}
int sumNaturalnum(int n){
if(n==0)
{
return n;
}
else{
return (n+sumNaturalnum(n-1));
}
}
When the above code is executed it produces the following output
Enter a natural numnber 50 The sum of natural numbers 1 to 50 : 1275
This program allows the user to enter a maximum number. and it displays addition of numbers from 1 to given number using recursive function in C language
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