int a;
a = 0;
std::cout << "1) " << a++ << std::endl;
std::cout << "2) " << a << std::endl;

a = 0;
std::cout << "3) " << ++a << std::endl;
std::cout << "4) " << a << std::endl;


//ВЫВОД:
1) 0
2) 1
3) 1
4) 1