sub mySub{
  my $Arg = shift;
}

sub mySub2{
  my ($Arg) = @_;
}

##</code><code>##

sub test{
  $_[0] = 'New Value';
}

my $Var = 'Hi there';
print "$Var\n";
test ($Var);
print "$Var\n";

##</code><code>##

Hi there
New Value