Process.h or cstdlib for exit() ??

Question

In my C++ text book it's written that inorder to use exit() function we need to declare <process.h> but internet says <cstdlib>. Which one is correct ??

Answer 1

The internet.

Here is some info on process.h
https://en.m.wikipedia.org/wiki/Process.h

In particular note the date of its creation (late 80's)

Answer 2

yeah it's very old