Note: This is not a real function, but a language construct.
Note: PHP version >= 4.2.0 does NOT print the status if it is an integer.
The exit() function terminates execution of the script. It prints status just before exiting.
If status is an integer, that value will also be used as the exit status. Exit statuses should be in the range 1 to 254, the exit status 255 is reserved by PHP and shall not be used.
Note: The die() function is an alias for exit().
See also: register_shutdown_function().