Re: Perl realted..?

[Dave Sherohman <dave@sherohman.org>]

On Fri, Jan 11, 2008 at 01:51:44AM -0800, pedxing wrote:
> But the point is that scope doesn't change in a loop, but it
> does in a subroutine.

You are incorrect.  Every set of { braces } is its own (sub)scope,
regardless of whether they are separated out into a sub or not.

~$ perl -w -e ' { my $last = "foo"; } print "$last\n"; '
Name "main::last" used only once: possible typo at -e line 1.
Use of uninitialized value in concatenation (.) or string at -e line 1.

~$ perl -w -e ' my $last; { $last = "foo"; } print "$last\n"; '
foo

Or, if you like the code from the original question better, try

perl -w -e 'while (<>) { my $last = $_ } print "$last\n"; '

and it *will* complain about $last being undefined after the loop exits:

~$ perl -w -e 'while (<>) { my $last = $_ } print "$last\n"; ' < .bashrc
Name "main::last" used only once: possible typo at -e line 1.
Use of uninitialized value in concatenation (.) or string at -e line 1, <> line 51.

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