circular.pm

PERL语言资料 可以用于PERL程序设计

#!/usr/bin/perl
# Fig. 14.18: Circular.pm
# Using the DESTROY function to destroy objects.

package Circular;

use strict;
use warnings;

sub new {
   my $class = shift();
   
   my $a;
   my $b = \$a;

   $a = \$b;
   
   my $self = {};

   $self->{ name } = shift();
   $self->{ Circle } = \$a;
   
   bless( $self, $class );
   return $self;
}

sub sayHi {
   my $self = shift();

   print( "$self->{ name } says hi.\n" );
}

sub DESTROY {
   my $self = shift();
   
   print( "Destroying $self->{ name }.\n" );   
   ${ $self->{ Circle } } = undef;
}

return 1;

###########################################################################
#  (C) Copyright 2001 by Deitel & Associates, Inc. and Prentice Hall.     #
#  All Rights Reserved.                                                   #
#  DISCLAIMER: The authors and publisher of this book have used their     #
#  best efforts in preparing the book. These efforts include the          #
#  development, research, and testing of the theories and programs        #
#  to determine their effectiveness. The authors and publisher make       #
#  no warranty of any kind, expressed or implied, with regard to these    #
#  programs or to the documentation contained in these books. The authors #
#  and publisher shall not be liable in any event for incidental or       #
#  consequential damages in connection with, or arising out of, the       #
#  furnishing, performance, or use of these programs.                     #
###########################################################################