---
name: "Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA"
section: "3pm"
platform: "linux"
package: "perl-perl-critic"
version: "1.156-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA"
---

# Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA(3pm)

Employ "use parent" instead of "@ISA".

## NAME

Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA - Employ "use parent" instead of "@ISA".

## AFFILIATION

This Policy is part of the core Perl::Critic distribution.

## DESCRIPTION

Conway recommends employing `"use parent qw(Foo)"` instead of the usual `"our @ISA = qw(Foo)"` because the former happens at compile time and the latter at runtime.  The parent pragma also automatically loads `"Foo"` for you so you save a line of easily-forgotten code.

The original version of this policy recommended base instead of parent, which is now obsolete.

## CONFIGURATION

This Policy is not configurable except for the standard options.

## AUTHOR

Chris Dolan \<cdolan@cpan.org\>

## COPYRIGHT

Copyright (c) 2006-2022 Chris Dolan.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.