EvenSum

import java.util.Scanner;

class EvenSum {

    public static void main(String[] args) {
        System.out.println("Enter the number up to which you want to sum:");
        Scanner sc=new Scanner(System.in);
        int topNumber = sc.nextInt();
        int sum = sumOfEvenNumbersUpTo(topNumber);
        System.out.println("The sum of Even numbers up to and including " + topNumber + " is " + sum);
    }

    protected static int sumOfEvenNumbersUpTo(final int topNumber) {
        int sum = 0;
        for (int thisNumber = 1; thisNumber <= topNumber; ++thisNumber) {
            final boolean isAnEvenNumber = thisNumber % 2 == 0;
            if (isAnEvenNumber) {
                sum = sum + thisNumber;
            }
        }
        return sum;
    }

    public static int sumOfEvenNumbersUpToB(final int topNumber) {
        if (topNumber > 0) {
            final int evenTopNumber = topNumber - topNumber % 2;
            return (evenTopNumber * evenTopNumber / 2 + evenTopNumber) / 2;
        } else {
            return 0;
        }
    }
}