Thread: Abstract and code output

Please explain me the output

Output is : 0

class ClassOne
{
    int methodOne(int i, int j)
    {
        return i++ + ++j - ++i - j++;
    }
}
 
abstract class ClassTwo extends ClassOne
{
    abstract int methodOne(int i, int j, int k);
 
    @Override
    int methodOne(int i, int j)
    {
        return methodOne(i, j, i+j);
    }
}
 
class ClassThree extends ClassTwo
{
    @Override
    int methodOne(int i, int j, int k)
    {
        return --i - j-- + ++k - i++ + ++j - k--;
    }
}
 
public class MainClass
{
    public static void main(String[] args)
    {
        ClassOne one = new ClassOne();
 
        ClassThree three = new ClassThree();
 
        System.out.println(three.methodOne(one.methodOne(10101, 20202), one.methodOne(20202, 10101)));
    }
}

To explain the output, you need to first understand how the increment operators work. Are you having trouble understanding the difference between j++ and ++j, for instance?