Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw
 
PerlMonks  

How can I make one class extend another one?

by Anonymous Monk
on Apr 20, 2000 at 20:27 UTC ( #8181=categorized question: print w/replies, xml ) Need Help??
Contributed by Anonymous Monk on Apr 20, 2000 at 20:27 UTC
Q&A  > object-oriented programming


Answer: How can I make one class extend another one?
contributed by chromatic

Inheritance is very easy in Perl. Assuming we have a class PerlMonk, we could create a new class called vroom that extends the first:

package vroom; @ISA = qw ( PerlMonk );
From then on, for any method called on an instance of vroom that isn't defined immediately in the class, Perl will search the classes named in @vroom::ISA for those methods.

That is, PerlMonk::dispense_wisdom() is available via $vroom->dispense_wisdom() even if there is no vroom::dispense_wisdom().

Note that the @ISA array can contain lots of parent classes. Note also that they are searched left-to-right, depth first.

Answer: How can I make one class extend another one?
contributed by brother ab

package Child; use base qw(Mother Father);

base pragma not only includes extended classes in @INC, but 'require's them.

Additionally, it is integrated with fields pragma (if you like strict data members protection)

Please (register and) log in if you wish to add an answer



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    [perldigious]: So I don't envy you mountain guys if you have to drive in the winter, even with tire chains.
    MidLifeXis waves.
    [stevieb]: man, I absolutely LOVE driving in the worst winter conditions. In the mountainous roads, there are extremely few (if any) other drivers. I love the challenge. I've been doing extreme off-road my whole life, and as I said, I'm always well...
    [stevieb]: ...prepared for even the very worst
    Discipulus seems a part of the globe very unfrindly with Kawasaki riders..
    [thezip]: My doggies love it when it snows
    [perldigious]: As long as you are a good "boy scout" stevieb, more power to you... but I like my Jeep, and don't like the idea of rolling it or crashing it in to anything. :-)
    [thezip]: Me, not as much.
    [perldigious]: Mine too thezip, especially my German Shepherd. He looks like he is about to die of heat exhaustion all summer, so he goes nuts when winter comes and he can play in the snow.

    How do I use this? | Other CB clients
    Other Users?
    Others surveying the Monastery: (11)
    As of 2016-12-06 16:48 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      On a regular basis, I'm most likely to spy upon:













      Results (112 votes). Check out past polls.