Java definition of % (remainder operator)
The Java programming language provides operators that perform addition, subtraction, multiplication, and division. There's a good chance you'll recognize them by their counterparts in basic mathematics. The only symbol that might look new to you is "%", which divides one operand by another and returns the remainder as its result.
(see source of reference here)
If you want to create a modulo function that returns only numbers in the range [0, n) when you ask for modulo n you will have to write it (simple).