The @ISA array is used in a package to tell Perl where to find a method if that method is not defined in said package. This is known as "inheritance". If I want to subclass Foo as Foo::Bar, I would do this:

    package Foo::Bar;
    use strict;
    use Foo; # don't forget this line!
    use vars qw/ @ISA /;
    @ISA = qw/ Foo /;

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That sets Foo as a base class of Foo::Bar. Further, if Foo has a base classes, Perl will search through them for a method call to a Foo::Bar object (or class method) in order to find something useful.

I can't think of any problems that using a scalar named $ISA would cause, but you are right that it could be bad form.

Now, since your question was "Void for Vagueness" :), I have to ask: did I answer it?

Cheers,
Ovid

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In reply to (Ovid) Re: A question of Inheritance by Ovid
in thread A question of Inheritance by tradez

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