You say "dereferencing", but at the same time "$arrayref". That's confusing.

To dereference an array reference returned from a subroutine, you can use:

my @array = @{ sub_returning_aref() };
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To get the actual reference, no dereferencing is needed:

my $aref = sub_returning_aref();
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On the other hand, if a subroutine returns a list, you can assign it directly to an array:

my @array = sub_returning_list();
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To create an array reference, you need to create an anonymous array, as the subroutine returns a list, not an array.

my $aref = [ sub_returning_list() ];
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There's nothing special about keys.

my @array = keys %hash;
my $aref  = [ keys %hash ];
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