You are viewing the version of this documentation from Perl 5.8.6. View the latest version



base - Establish IS-A relationship with base classes at compile time


package Baz;
use base qw(Foo Bar);


Allows you to both load one or more modules, while setting up inheritance from those modules at the same time. Roughly similar in effect to

package Baz;
    require Foo;
    require Bar;
    push @ISA, qw(Foo Bar);

If any of the listed modules are not loaded yet, base silently attempts to require them (and silently continues if the require failed). Whether to require a base class module is determined by the absence of a global variable $VERSION in the base package. If $VERSION is not detected even after loading it, <base> will define $VERSION in the base package, setting it to the string -1, set by

Will also initialize the fields if one of the base classes has it. Multiple inheritence of fields is NOT supported, if two or more base classes each have inheritable fields the 'base' pragma will croak. See fields, public and protected for a description of this feature.


Base class package "%s" is empty. was unable to require the base package, because it was not found in your path.


This module was introduced with Perl 5.004_04.


Due to the limitations of the implementation, you must use base before you declare any of your own fields.