This equation gives different result in "Python" and "Java"

Question

I am converting a program written in Python to Java. There is an equation in Python code: (19 - 20) % 91 and it Java version is (19 - 20) % 91 means same. This equation is giving the answer 90 in Python but, in Java it is giving the answer -1. How do I modify this equation from Python to Java so that it can work and run properly?

Does this answer your question? [Mod in Java produces negative numbers](https://stackoverflow.com/questions/5385024/mod-in-java-produces-negative-numbers) — Yanirmr, Nov 03 '20 at 11:40
look that question: https://stackoverflow.com/questions/5385024/mod-in-java-produces-negative-numbers — Yanirmr, Nov 03 '20 at 11:40
The java code already runs properly, according to the definition of the java language. — NomadMaker, Nov 03 '20 at 12:25

score 1 · Accepted Answer · answered Nov 03 '20 at 11:59

The problem here is that in Python the % operator returns the modulus and in Java it returns the remainder. These functions give the same values for positive arguments, but the modulus always returns positive results for negative input, whereas the remainder may give negative results. There's some more information about it in this question.

You can find the positive value by doing this:

int i = (19-20) % 91;
if (i<0) i += 91;

Or you can use Math.floorMod():

Math.floorMod((19-20), 91);

This equation gives different result in "Python" and "Java"

1 Answers1