Have a look at ref 
my ( $scalar, @array );

foo( \$scalar );
foo( \@array  );

sub foo {
    print ref $_[0], "\n";
}
__END__
SCALAR
ARRAY

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Unless I state otherwise, all my code runs with strict and warnings

In reply to Re: Determining the type of a subroutine parameter by FunkyMonk
in thread Determining the type of a subroutine parameter by esr

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