注: This is not a real function, but a language construct.
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.
注: The current CVS version does NOT print the status if it is an integer.
注: The die() function is an alias for exit().