Corrent. '->' dereferences a reference to a hash. Note that I do not have to explicitly tell Perl that I am dereferencing a reference to a hash, Perl will work it out.

I have constructed the following example to show how to dereference a hash in a sub and modify its contents.

use strict;
use Data::Dumper;

my %hash = qw/ A 1 B 2 /;

print 'Before sub:'.Dumper(\%hash);
modify_hash(\%hash);
print 'After sub:'.Dumper(\%hash);

sub modify_hash{
 my $h_ref = shift;

 $h_ref->{C}    = '3';
 $h_ref->{D}    = '4';
 %{$h_ref}->{E} = '5';  # this is what it's doing
 $$h_ref{F}     = '6';  # you could do this too
}

[download]
And the output is -
Before sub:$VAR1 = {
          'A' => '1',
          'B' => '2'
        };
After sub:$VAR1 = {
          'F' => '6',
          'A' => '1',
          'B' => '2',
          'C' => '3',
          'D' => '4',
          'E' => '5'
        };

[download]

In reply to Re: Re: Re: Passing hashes by reference by Roger
in thread Passing hashes by reference by wolis

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