Re: Using map to create a hash/bag from an array

The idiomatic way to do that in Perl is @hash{qw(a b c)} = (1) x 3;:

use strict;
use warnings;
use Data::Dumper;

my %hash;
@hash{qw(a b c)} = (1) x 3;
print Dumper (\%hash);
[download]

Prints:

$VAR1 = {
          'c' => 1,
          'a' => 1,
          'b' => 1
        };
[download]

DWIM is Perl's answer to Gödel

Comment on Re: Using map to create a hash/bag from an array Select or Download Code

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Re^2: Using map to create a hash/bag from an array by bart (Canon) on Dec 18, 2005 at 10:45 UTC
Except, IMHO, the hash values are irrelevant. Codewise, it's easier to use undef as hash values: your `@hash{qw(a b c)} = (1) x 3;` [download] then becomes `@hash{qw(a b c)} = ();` [download] That's a lot shorter, isn't it? And no need to count items.	[reply] [d/l] [select]
Re^3: Using map to create a hash/bag from an array by GrandFather (Sage) on Dec 18, 2005 at 11:21 UTC
And faster too (making the obvious benchmark addition): `Rate set map map++ GF Bart set 2288/s -- -84% -91% -92% -93% map 14566/s 537% -- -46% -48% -58% map++ 26756/s 1070% 84% -- -4% -23% GF 27881/s 1119% 91% 4% -- -19% Bart 34580/s 1412% 137% 29% 24% --` [download] See Re: Using map to create a hash/bag from an array for the original code DWIM is Perl's answer to Gödel	[reply] [d/l]