what does x— or x++ do here?

Question

it is a silly Q for most of u - i know - but i one of the beginner here, and I can not understand why the output in here are 12 what does this (x--) do to the resu

Answer 1

x++ increments x after x being evaluated. ++x increments x before x being evaluated.

 int x = 0;
 print(++x); // prints 1
 print(x); // prints 1

 int y = 0;
 print(y++); // prints 0
 print(y); // prints 1

The same goes for --