Why does this not work when trying to find the sum of all multiples of 3 and 5 in 1000?

Question

There are a lot of questions on here about the project Euler question about finding the sum of all the multiples of 3 and 5 below 1000, but I am a beginner at Java , and I attempted to make my own program to try and figure this out.The problem with my code is, it keeps giving the answer 466 . 466 is the wrong answer to this problem, so I'm wondering what I did wrong.

Here is my code.

package sumofmultiples;

public class sumofMultiples{
    public static void main(String[] args){
        int number = 1; //<- This is the number that we are checking to be a multiple.
        int totalNumber= 0; //<- Total number of multiples counted so far.
        while (number < 1000){
            if ((number % 3) == 0){
                totalNumber++;
                //The number is a multiple of 3.
            } else if ((number % 5) == 0){
                totalNumber++;
                //The number is a multiple of 5
            }
            number++; //<- Move on to the next number.
        }
        System.out.println(totalNumber); //<- Print results
    }
}

Answer 1

You are calculating the number of multiples. Not their sum. The totalNumber++ is going to be incremented whenever a number is a multiple of 3 or 5, but the 'multiple' is not stored.

Change totalNumber++ to totalNumber += number and your problem is solved.

package sumofmultiples;

public class sumofMultiples{
    public static void main(String[] args){
        int number = 1; //<- the number that we are checking to be multiple.
        int totalNumber= 0; //<- Total number of multiples counted so far.
        while (number < 1000){
            if ((number % 3) == 0 || (number % 5) == 0){ 
                totalNumber += number;
            } 
            number++; //<- Move on to the next number.
        }
        System.out.println(totalNumber); //<- Print results
    }
}