perl> $_ = 'Foo'; print;
Foo
 perl> print;
print;

 perl> my $a = 'Bar'; print $a;
Bar
 perl> print $a;
Use of uninitialized value in print at (eval 4) line 1, <> line 4.

##</code><code>##

#!perl            # header
use warnings;     # enable warnings
use diagnostics;  # explain warnings
                  # code to test:
print "Hey world, I'm coming!!!\n";

##</code><code>##

perl C:\test.pl