print $scalar1 .= $scalar2;

##</code><code>##

my $arg = 1;
someMutator( $arg );
print $arg;

##</code><code>##

print someMutator( 1 );

##</code><code>##

my $widget = Tk::SomeWidget->new( ... );
$widget->Add( ... );
$widget->pack( ... );

##</code><code>##

my $widget = Tk::SomeWidget->new( 
    ... 
)->Add(
   ...
)->pack( ... );