use strict;
use warnings;

my $a = 2;
my @x = ( 1 .. 5 );
my @y = @x;

scale_ary2($a, @y);
print "\@x = @x \n";
print "\@y = @y \n";

sub scale_ary2 {
    my $scale = shift;
    $_ *= $scale for @_;
    1;
}