Inheritance in Perl 5 is very simple.
To do so, you simply declare a class array called @ISA.
This array will be used to store the name and parent class(es)
of the new species. Whenever the new class is used, it will
have this reference to its lineage and be able to check there
against method calls and properties.
For example, to define a subclass of
Cat, you could use
package NorthAmericanCat;
@NorthAmericanCat::ISA = ("Cat");
sub new {
[. . . Code goes here . . .]
}
Notice that in perl 5, package references
are handled using the "::" notation. Finally, note that
instantiation of an inherited class will work just the same
as it did without inheritance.
