How do I combine arrays and array of hashes?

bradcathey has asked for the wisdom of the Perl Monks concerning the following question:

Perl uses a little magic to combine arrays, but the more complex reference to an AoH requires a bit more magic

ARRAYS:

my @aoh1 = qw (value1 value2);
my @aoh2 = qw (value3 value4);

@aoh2 = (@aoh1, @aoh2);
[download]

output:

@aoh2 = ('value1',
         'value2',
         'value3',
         'value4'
        );
[download]

AoH's:

@aoh1 = ({ 'key1' => 'value1', 
           'key2' => 'value2' });
@aoh2 = ({ 'key3' => 'value3',
           'key4' => 'value4' });

@aoh2 = (@aoh1, @aoh2);
[download]

output:

@aoh2 = (
          {
            'key2' => 'value2',
            'key1' => 'value1'
          },
          {
            'key4' => 'value4',
            'key3' => 'value3'
          }
        );
[download]

Comment on How do I combine arrays and array of hashes? Select or Download Code

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Re: How do I combine arrays and array of hashes? by fullermd (Vicar) on Dec 31, 2008 at 06:46 UTC
The question isn't quite clear as to the desired outcome. I'll read it as: you want to turn two one-element arrays, each of whose element is a hashref, into one one-element array, whose element is a hashref of the combined hashes. That seems a little weird. But here's one idea: `@aoh2 = ({map { %$_ } (@aoh1, @aoh2)});` [download] It does the same thing with multiples; e.g., if one of the arrays has multiple hashrefs in it, it still gets rolled up into one output: `@aoh1 = ({ 'key1' => 'value1', 'key2' => 'value2' }); @aoh2 = ({ 'key3' => 'value3', 'key4' => 'value4' }, { 'key5' => 'value5', 'key6' => 'value6' }); @aoh2 = ({map { %$_ } (@aoh1, @aoh2)});` [download] Output: `@aoh2 = ( { 'key5' => 'value5', 'key2' => 'value2', 'key6' => 'value6', 'key4' => 'value4', 'key1' => 'value1', 'key3' => 'value3' } );` [download]	[reply] [d/l] [select]
Re^2: How do I combine arrays and array of hashes? by eye (Chaplain) on Jan 01, 2009 at 11:28 UTC
As fullermd notes, the OP's question is a bit unclear. If the intent was to combine arrays of hashes and produce a simple array (an operation not subject to problems with conflicting keys), fullermd's solution can be modified to: `@aoh3 = map {values %$_} (@aoh1, @aoh2);` [download]	[reply] [d/l]