Re: split every other value

Replies are listed 'Best First'.
Re^2: split every other value by Prior Nacre V (Hermit) on Aug 07, 2004 at 00:29 UTC
And even faster with optimisation: `my (@evens, @odds); my $ra_all = [ \@evens, \@odds ]; map { push @{$ra_all->[$_ % 2]}, $_ } split /,/, $scalar;` [download] Regards, PN5	[reply] [d/l]
Re^3: split every other value by Aristotle (Chancellor) on Aug 07, 2004 at 00:38 UTC
I don't understand the point of the third arrayref. I also find it easier on the eyes with a foreach, but to each his own. `my ( @evens, @odds ); my @all = ( \@even, \@odd ); push @{ $all[ $_ % 2 ] }, $_ for split /,/, $scalar;` [download] Brevity, but don't do this at home: you can combine the first two lines into `my @all = \my ( @evens, @odds );` [download] Makeshifts last the longest.	[reply] [d/l] [select]
Re^4: split every other value by Prior Nacre V (Hermit) on Aug 07, 2004 at 01:56 UTC
3rd arrayref That's there for historical reasons :-) Actually, this is true, it was there in my first (pre-post) take and it basically got left in. One less dereference is good. Thanks. map vs. foreach For many years I only ever used foreach but that was because it wasn't available until Perl5. I then didn't use it for much the same reasons you give. About 2-3 years ago I was doing some benchmarking and was amazed at how much faster map was (especially the map BLOCK LIST form) - grep had a similar speed efficiency. I still use foreach; however, usage has made the map format easier on the eyes and I use it on a daily basis without really given it a second thought. \my LIST I was aware of this. It fails in extraordinarily interesting ways on various 5.6 versions. I now avoid it like the plague! So that leaves us (or at least me) with: `my (@evens, @odds); my @all = (\@evens, \@odds); map { push @{$all[$_ % 2]}, $_ } split /,/, $scalar;` [download] Regards, PN5	[reply] [d/l]