in reply to mapping two arrays into anon hash

Use Hash Slices: 
use Data::Dumper;
my @usual = qw( data email stuff );
my @values = qw( 33 44 55 );
my %hash;
@hash{ @usual } = @values;
print Dumper \%hash;

[download]

-----------------------------------------------------
Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain
"I can see my house from here!"
It's not what you know, but knowing how to find it if you don't know that's important

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Re: Re: mapping two arrays into anon hash
by agoth (Chaplain) on Jan 08, 2002 at 17:12 UTC
    I know about hash slices !!, and am using one in the sub...
    I'm trying to slice anonymously without defining the hash explicitly, in order to build up a data structure with the minimum amount of effort..
    looking for { username => 'fred' , @{}{@usual} fancyslice @values };
    which led me to the @_{@ary1}; %_ monstrosity...
[reply]
      You're asking for the impossible, or if it is, it's going to be an ugly mess. Sure, it's nice to get a simple result that doesn't use extra variables, but if it becomes unreadible, then you're going to confuse others as to the meaning of your code. In this case, using a temporary hash is not going to increase your memory usage save for maybe an extra byte if you create a reference to the hash, and the code will be much easier to read.

      But here's another solution that doesn't use any extra variables beyond $_: 

      use Data::Dumper;
my @names = qw ( web email stuff );
my @values = qw( 33 44 55 );
my $ref = { map { $names[$_] => $values[$_] } (0..$#names) };
print Dumper $ref;

      [download]
      (It's still not as clean as using the hash slice, IMO, but if that's what you want...)

      -----------------------------------------------------
      Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain
      "I can see my house from here!"
      It's not what you know, but knowing how to find it if you don't know that's important

[reply]
[d/l]
        Thanks for that, that's it.

        Don't worry! I have no intention of leaving it in the code, and will probably opt for the subroutine method anyway, I do generally work with half an eye on maintainability.
        What REALLY bugged me was not being able to figure out HOW to shortcut it even if I wasn't going to use the shortcut in the end product...There might be 8 WTDI in this case but i knew there was a shorter WTDI somewhere....

[reply]

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