On Oct 30, 2009, at 9:26 AM, Abigail wrote:
On Fri, Oct 30, 2009 at 09:05:51AM +0000, Mark Fowler wrote:
Hello,
I have in the past coded things to only discover later that someone
else has already written what I have toiled away on, only better. So
this time, I'm asking the experts[1] first.
I have an array in Perl 5 [2]. I want *every* *other* element from
it. There is, of course, more than one way to do it:
my @new;
foreach (my $i = 0; $i < @old; $i++) {
push @new, $old[ $i ];
}
Assuming no duplicates or references, and an even sized list:
my @odds = keys %...@old}};
my @evens = values %...@old}};
Oh, and it won't preserve order either. But at least it's not ugly.
And it doesn't need additional variables.
Abigail "The blue coat is mine"
Why not something lengthier like
@evens = @list[ grep {!($_ & 1)} (0 .. $#list) ];
which should preserve order and doesn't care about list size?
Mike
--
Mike Stok <m...@stok.ca>
http://www.stok.ca/~mike/
The "`Stok' disclaimers" apply.
