C Exercises: Display n natural numbers and their sum

C For Loop: Exercise-3 with Solution

Write a program in C to display n terms of natural numbers and their sum.

Visual Presentation:

Sample Solution:

C Code:

#include <stdio.h>  // Include the standard input/output header file.

int main() {
    int i, n, sum = 0;  // Declare variables 'i' for loop counter, 'n' for the number of terms, and 'sum' to store the sum.

    printf("Input Value of terms : ");  // Print a message to prompt user input.
    scanf("%d", &n);  // Read the value of 'n' from the user.

    printf("\nThe first %d natural numbers are:\n", n);  // Print a message to indicate the output.

    for (i = 1; i <= n; i++) {  // Start a for loop to iterate from 1 to 'n'.
        printf("%d ", i);  // Print the current value of 'i'.
        sum += i;  // Add the current value of 'i' to the sum.
    }

    printf("\nThe Sum of natural numbers upto %d terms : %d \n", n, sum);  // Print the sum of natural numbers.
    return 0;
}

Sample Output:

Input Value of terms : 7                                                                                      
                                                                                                              
The first 7 natural number is :                                                                               
1 2 3 4 5 6 7                                                                                                 
The Sum of Natural Number upto 7 terms : 28 

Explanation:

for (i = 1; i <= n; i++) {
  printf("%d ", i);
  sum += i;
}

In the above for loop, the variable i is initialized to 1, and the loop will continue as long as i is less than or equal to the value of variable 'n'. In each iteration of the loop, the printf() function will print the value of i to the console, followed by a space character. Additionally, the value of i will be added to the variable 'sum' in each iteration of the loop.

Finally, the loop will increment the value of i by 1, and the process will repeat until the condition i<=n is no longer true.

Flowchart:

C Programming Code Editor:

Previous: Write a C program to find the sum of first 10 natural numbers.
Next: Write a program in C to read 10 numbers from keyboard and find their sum and average.