You're trying to be too complicated. Instead of taking a hash and removing what shouldn't be there, why don't you just create a new hash by adding what should be there. Something along the lines of: 

my %hash2;
for (@ary) {
    $hash2{$_} = $hash1{$_} if exists $hash1{$_};
}
undef %hash1;

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In reply to Re: Mapping array over a hash by dragonchild
in thread Mapping array over a hash by agoth

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