1. Introduction

Natural numbers are a part of number system which includes all the positive integers from 1 till infinity and are used for counting. In this Java program, we are going to find the sum of natural numbers using a while loop. This is a fundamental example showcasing the usage of loops and conditional statements in Java.

2. Program Steps

1. Define a class named SumOfNaturalNumbers.

2. Inside the main method, define an integer num up to which we want to calculate the sum.

3. Initialize two variables sum and i to 0. sum will hold the final result, and i is our counter variable.

4. Use a while loop to iterate until i is less than or equal to num.

5. In each iteration, add the value of i to sum.

6. Increment the value of i in each iteration.

7. After exiting the loop, print the value of sum.

3. Code Program

public class SumOfNaturalNumbers { // Step 1: Define a class named SumOfNaturalNumbers

    public static void main(String[] args) { // Main method
        int num = 100; // Step 2: Define an integer num up to which we want to calculate the sum
        int sum = 0; // Step 3: Initialize sum to 0
        int i = 1; // Step 3: Initialize counter variable i to 1

        // Step 4: Use a while loop to iterate until i is less than or equal to num
        while (i <= num) {
            sum = sum + i; // Step 5: In each iteration, add the value of i to sum
            i++; // Step 6: Increment the value of i in each iteration
        }

        // Step 7: Print the value of sum
        System.out.println("Sum of Natural Numbers up to " + num + " is: " + sum);
    }
}

Output:

Sum of Natural Numbers up to 100 is: 5050

4. Step By Step Explanation

– Step 1: We define a class named SumOfNaturalNumbers.

– Step 2: Inside the main method, we define an integer num up to which we want to calculate the sum. In this example, we have taken num as 100.

– Step 3: We initialize two variables sum and i to 0 and 1 respectively. sum will hold the final result, and i is our counter variable.

– Steps 4 to 6: We use a while loop to iterate until i is less than or equal to num. In each iteration, we add the value of i to sum and increment the value of i.

– Step 7: After exiting the loop, we print the value of sum, which holds the sum of natural numbers up to num.