“C - C++” joke about postfix/prefix operation ordering

Question

My friend sent me a joke:

Q. What\'s the difference between C and C++?

A. Nothing, because: (C - C++ == 0)

I tried to change

Answer 1

Because in the first example, c starts out 10. c++ increments c and returns 10, so the second c now evaluates to 11 since it was incremented. So the ultimate expression evaluated is 10 - 11, which equals -1.

In the second example, ++c increments c again but returns 12 since it is a pre-increment. The second c evaluates to 12 as well, since it's the new value stored in c. So that expression ultimately is evaluated as 12 - 12, which equals 0.