use strict;
if (1) {
  my $foo = "hi";
}
print $foo."\n";

__OUTPUT__
Global symbol "$foo" requires explicit package name at scope.pl line 5
+.
Execution of scope.pl aborted due to compilation errors.
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me stupid, you are absolutely right fletcher.

The "my" operator declares the listed variables to be lexically confined to the enclosing block, conditional ("if/unless/elsif/else"), loop ("for/foreach/while/until/continue"), subroutine, "eval", or "do/require/use"'d file.

502 $ perl -we'use strict;if(1){my $foo="foo"};print $foo'
Global symbol "$foo" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.
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edit: beaten

This is still a bug. Try this:

use strict;
use warnings;

if (1) {
    my $a = 100;
}
print $a;
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If you are not allowed to ref that $a any more, once exit that if block, there is absolutely no point not to garbage collect it.

there is absolutely no point not to garbage collect it

Yes there is. It might be cheaper, (read: Lazier) to not garbage collect it at all, and just let the program fall off the end of the world. Just because you can, doesn't mean it's worth spending the effort to do so.

It was only with the advent of mod_perl and similar long-running persistent perl processes that any serious effort started to be devoted to keeping track of perl's resource usage. It used to be that it was cheaper not to do anything, because in a few milliseconds time, the pages used by the process would be reclaimed by the OS when program ended anyway.

And given perl's propensity for trading off memory for speed, it doesn't really surprise me that we see the behaviour demonstrated by the OP.

don't use $a as a variable, this is confusing when used with strict
---------------------------
Dr. Mark Ceulemans
Senior Consultant
BMC, Belgium