How to Find the Sum of Natural Numbers in Java?

You can find the sum of natural numbers in Java using a loop or a formula.

Using a Loop

1. Initialize variables: Declare a variable to store the sum and set it to 0. Declare another variable to represent the number of natural numbers you want to sum.
2. Iterate through the numbers: Use a loop (for loop or while loop) to iterate from 1 to the specified number.
3. Add each number to the sum: Inside the loop, add the current number to the sum variable.
4. Print the sum: After the loop completes, print the value of the sum variable.

Here's an example using a for loop:

public class SumOfNaturalNumbers {
    public static void main(String[] args) {
        int num = 10; // Change this to the desired number of natural numbers
        int sum = 0;

        for (int i = 1; i <= num; i++) {
            sum += i;
        }

        System.out.println("The sum of natural numbers up to " + num + " is: " + sum);
    }
}

Using a Formula

You can also use the formula for the sum of an arithmetic series to calculate the sum of natural numbers:

Sum = (n (n + 1)) / 2*

Where n is the number of natural numbers.

Here's an example using the formula:

public class SumOfNaturalNumbers {
    public static void main(String[] args) {
        int num = 10; // Change this to the desired number of natural numbers
        int sum = (num * (num + 1)) / 2;

        System.out.println("The sum of natural numbers up to " + num + " is: " + sum);
    }
}

Choosing the Right Approach

Using a loop is more intuitive and easier to understand for beginners. However, the formula is more efficient, especially for large values of n.