为什么余数（模数）除法返回负数

Question

    x=-10 % -4;
    System.out.println("-10% -4 : "+x); //-2 second row

The output '-2' why in the answer is a negative value?

Answer 1

% is remainder division. It is the amount left over after the integer division.

x = -10 / -4; // == 2

and

x = -10 % -4; // == -2

The later can be thought of as -10 divided by -4 (which is 2) with a remainder of -2.

It might be easier to see if both answers were not the same absolute value.

x = -10 / -3; // == 3

and

x = -10 % -3;  == -1

Answer 2

Unfortunately that is the way the Java modulus operator works with negative numbers. If you want only positive remainder values then do a simple conversion like this:

if(x < 0){
    x = x * -1;
}