Today I learned (that unlike in python), if you mod a negative integer with a natural number, the answer won’t be adjusted to be accurate. Instead, it will return negative mod answers.

In python, -1 % 4 yields 3 (adjusted answer)

But, in golang, -1 % 4 yields -1

To fix it, we can to add the denominator to the final answer to get the accurate mod (but this is manual grunt work).

mod_val = ((numerator) % denominator) + denominator

So, if you want to ‘black-boxify’ it (if you will), you can create an expression so you don’t have to worry if the numerator is negative or positive.

accurate_mod_val = (((numerator) % denominator) + denominator) % denominator

This expression is implementation agnostic, so you can use this anywhere :)

This hack could help programmers gain back a ton of time in dev-loops. Hope you found this helpful!

👋 ⸻ @TnvMadhav