Re: my $1

$1 and $2 are package variables, not lexicals. You can nest their contents with local. Lexical $_ is a new addition from 5.10.0 onwards.

Best practice is simply to copy out $1 and ilk to lexicals, the way you're doing it (but within a conditional, checking that the match succeeded).

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Comment on Re: my $1

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Re^2: my $1 by mltucker (Initiate) on Apr 23, 2009 at 21:26 UTC
Thanks for the reply. Ok, so could I use `local` for $1 and $2 in the same way that I use `my` for $_? This isn't working how I expected it to. I'm not sure if this is relevant, but the one that I'm having trouble with is the multiplication, where I use both the originals and the recursive call results: `return "($1)(".diff($2).")+($2)(".diff($1).") if m/(.+?)\*(.+)/;` [download] This works fine using `$capt1 = $1`, but I'm curious as to whether it can be done using `local` or with the double quotes... -Mark	[reply] [d/l] [select]

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Re^2: my $1
by mltucker (Initiate) on Apr 23, 2009 at 21:26 UTC

Thanks for the reply.

Ok, so could I use local for $1 and $2 in the same way that I use my for $_? This isn't working how I expected it to.

I'm not sure if this is relevant, but the one that I'm having trouble with is the multiplication, where I use both the originals and the recursive call results:

return "($1)*(".diff($2).")+($2)*(".diff($1).") if m/(.+?)\*(.+)/;
[download]

This works fine using $capt1 = $1, but I'm curious as to whether it can be done using local or with the double quotes...

[reply]
[d/l]
[select]