Re: getting array of values from hash

twinsen,
I hesitated to reply because I knew other monks would come up with a solution faster than I. I only would like to add grep for the possibility that the first array (@a1) contain non-keys as well.

#!/usr/bin/perl -w
use strict;
my %h1;
$h1{'key1'} = 'foo';
$h1{'key2'} = 'bar';
my @a1 = ( 'key1' , 'key2' , 'not_a_key');
my @a2 = grep defined , @h1{@a1};
print "$_\n" foreach(@a2);
[download]

Cheers - L~R

Comment on Re: getting array of values from hash Download Code

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Re^2: getting array of values from hash by adrianh (Chancellor) on Mar 25, 2003 at 10:33 UTC
I hesitated to reply because I knew other monks would come up with a solution faster than I. I only would like to add grep for the possibility that the first array (@a1) contain non-keys as well. Niggle :-) This doesn't check for non-keys. It checks that each key has a defined value. In the process it auto-vivifies each key in `@a1`, which is probably not what you want even if you are searching for keys with defined values. For example, after running your example `%h1` will be: `( 'key2' => 'bar', 'key1' => 'foo', 'not_a_key' => undef, )` [download] Also, what if you want a key with an undef value? If `@a1` might contain non-keys they something like this will do the job. `@a2 = @h1{grep exists $h1{$_}, @a1};` [download]	[reply] [d/l] [select]
Re: Re^2: getting array of values from hash by Limbic~Region (Chancellor) on Mar 25, 2003 at 13:08 UTC
adrianh, I jokingly said in the CB the other day that I wished Perl 6 would have a plug-in (literally), so that I could plug it into my brain and have it directly translate my thoughts to code. I guess I don't need to wait for Perl 6 - just have you around ;-) Thanks for writing what I was thinking! Cheers - L~R	[reply]