What is the difference here?

I'm sorry for that confusion. I think it has something to do with the type "double", but I could not find anything about that issue yet. Okay so here's my example. 1) First System.out result here: This is the first method: 136.0 2) Second System.out result here: This is the second method: 150.96 -> so why is this calculating different here? 150.96 should be fine in both cases.

public class Solution {
    public static void main(String[] args) {
        System.out.println("This is the first method: " + convertWeight(888));
        System.out.println("This is the second method: " + convertWeight2(888));
    }

    public static double convertWeight(int weightEarth) {

        double result;

        result = weightEarth / 100 * 17;

        return result;
    }

    public static double convertWeight2(int weightEarth) {

        double result;

        result = weightEarth * 0.17;

        return result;
    }
}

Thank you, I posted it under the comment of Tiym :)

OK, already i get it:) If you divide one "int" by another "int", the result is also just an "int". Even if you put the result in a variable of type "double"! So: "888" = int. "100" = int. So in line 11: 888/100 = not 8.88! But only a simple 8! And 8 * 17 is equal to 136. And then Java puts this 136 into the "double" type variable and then changes to 136.0. If you have two "int"-s and you want to get an exact dividing result, you must convert at least one "int" to double before the dividing with some trick. For example, in the case of 888/100: 888 / (100 + 0.0) (888 + 0.0) / 100 or: 888*0.01. But if you write the method like this:

double result = weightEarth;
result = result / 100 * 17;
return result;

in this case, you will also get the wanted correct result because the first line already converts the "weightEarth" "int" to a "double" (888.0).

Uffff... I thought that it was something like that.. Thank you Gellert! :)

You're welcome! :)