Why are empty expressions legal in C/C++?

Question

int main()
{
  int var = 0;; // Typo which compiles just fine
}

Answer 1

The most common case is probably

int i = 0;
for (/* empty */; i != 10; ++i) {
    if (x[i].bad) break;
}
if (i != 10) {
    /* panic */
}