Anonymous Monk,
There are at least 3 easy ways to do this:

  • Assign the hash = to the return value of the sub: %hash = build_hash(sub {return %new_hash});
  • Pass a hash reference to the sub and return a reference $hashref = build_hash(sub {return \%new_hash});
  • Pass a hash reference to the sub and modify the original - see below

    The first is usually considered bad form as there is too much copying going on and it will not allow you to pass more than one hash at a time. The second is my preferred method, but it looks like you were going for number 3. 

    #!/usr/bin/perl -w
use strict;
my %hash;
build_hash(\%hash);
print "$_ : $hash{$_}\n" foreach(keys %hash);

sub build_hash {
    my $hash_ref = shift;
    $hash_ref->{'key1'} = "foo";
    $hash_ref->{'key2'} = "bar";
}

    [download]
    By the way, if you are going to loop over the hash to get both the keys and values, each is typically considered the way to go.

    Cheers - L~R

    In reply to Re: Preserving hash structure after subroutine call by Limbic~Region
    in thread Preserving hash structure after subroutine call by Anonymous Monk

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