extracting a list from a lists of lists

tachekent has asked for the wisdom of the Perl Monks concerning the following question:

If I have a lists of lists, how do I copy one of the sub-lists into a new list?

I tried @newlist = $LoL[$n], but that always seems to evaluate $LoL$n in scalar context.

confused...

Comment on extracting a list from a lists of lists Download Code

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Re: extracting a list from a lists of lists by gjb (Vicar) on Jan 02, 2003 at 00:20 UTC
The list of list has references as elements, so writing the assignment as `@newlist = @{$LoL[$n]};` will dereference this reference to a list. Have a look at perldata and perlfaq4. Hope this helps, -gjb-	[reply] [d/l]
Re: extracting a list from a lists of lists by tadman (Prior) on Jan 02, 2003 at 01:08 UTC
As gjb mentioned, you can copy with a dereference. Sometimes it's not necessary to copy, though, so you can always just use the reference as is. Here's some examples: `my $ref = $LoL[$n]; my @ary = @{$LoL[$n]}; $ref->[0] = "Foo"; # Modifies @LoL directly $ary[0] = "Foo"; # Only modifies @ary copy foreach (@$ref) { ... } foreach (@ary) { ... }` [download]	[reply] [d/l]