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I believe this is your question:
"I have an array (@data_list) containing hash references. Each hash reference contains two keys, 'key' and 'value'. I want to turn this into one hash containing 'key'=>'value' pairs. How can I do this?"

My solutions below assume that you have unique key values, or are un-interested in collisions. In the case of a collision, the last reference to the key wins.

Here is a fully verbose version:

my %final_hash; foreach my $data_pair ( @data_list) { $key = $data_pair->{ key }; $value = $data_pair->{value}; $final_hash{ $key } = $value; } use Data::Dumper; print Dumper \%final_hash;

A shorter version:

my %final_hash = map { $_->{key} => $_->{value} } @data_list; #verify the output use Data::Dumper; print Dumper \%final_hash;
And how do we know they work? We test them.

Full version with tests:

#!/usr/bin/perl -w use strict; use Data::Dumper; use Test::More tests => 2; my @data_list = ( { key => 'correct', value => 'AAA' }, { key => 'correction', value => 'BBB' }, { key => 'date', value => '20090303' }, { key => 'date', value => '20090308' }, ); my $expected = { correct => 'AAA', correction => 'BBB', date => '20090303', date => '20090308', }; my %final_hash_long; foreach my $data_pair (@data_list) { my $key = $data_pair->{key}; my $value = $data_pair->{value}; $final_hash_long{$key} = $value; } my %final_hash_short = map { $_->{key} => $_->{value} } @data_list; is_deeply( \%final_hash_long, $expected, "long version works" ); is_deeply( \%final_hash_short, $expected, "short version works" );

In reply to Re^3: Array to hash converstion by spazm
in thread Array to hash converstion by gem555

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