Hi Monks,

I'm trying to write a subroutine that adds a key-value pair to an array of hashes declared in the main program. I'd like to pass the subroutine a reference to a particular hash in the array (say the first one), and then access the added key-value pair back in the main program. Here's an example: 
#!/usr/bin/perl

use strict;
use warnings;

my @array_of_hashes;

Add_key_and_value( $array_of_hashes[0], qw/ James Bond / );

print $array_of_hashes[0]{'James'}, "\n";  # Should print 'Bond'.

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Now, it works fine if I define Add_key_and_value like that: 
sub Add_key_and_value {
  $_[0]->{ $_[1] } = $_[2];
}

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However, I'd rather define the subroutine like that: 
sub Add_key_and_value {
  my( $ref, $key, $value ) = @_;
  $ref->{ $key } = $value;
}

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but this yields "use of uninitialized value in print...".

Could anyone explain to me what is wrong with the latter definition?

Thanks in advance.

In reply to Passing a reference to an element in an array of hashes by textual

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