How do I write a C++ factorial calculator with a for loop?

[MisterX]

You main function looks like this: int main (void), it means that your function must return an integer. [you can change it to void main (void), then you will not need any return...]

Actually, main implicitly returns 0 for C++, so (for the main function only) you may omit "return 0;"

void main(void) is not okay!

It is not what is specified by the standards.

The caller is expecting a return value, and that value should be 0 for success.

It could result in stack corruption.