Re: Polymorphism [was] [Fwd: Re: [PHP] Parents constructor]

Dave Goodchild wrote:

That is not polymorphism - that is multiple inheritance. Java can't do

well that clears up my misuse of the terminology!

that either, and uses a much cleaner method - interfaces. And interfaces are supported in php5. So php does allow it. Not polymorphism - multiple

no Interfaces are not a mechanism for mutliple inheritance (in php) - they don't allow definition of the of the body of functions on the signature. not that I want multiple inheritance - I live on the MI is evil side of town (even when I was calling MI by a different [and incorrect] name).

inheritance. Not multiple inheritance - interfaces.

you have fluff on the needle. (record is stuck) ;-)

On 03/05/06, *Jochem Maas* <jochem@iamjochem.com <mailto:jochem@iamjochem.com>> wrote:

    -------- Original Message --------

    On Fri, 2006-03-24 at 10:50, Jochem Maas wrote:

Pham Huu Le Quoc Phuc wrote:

I want to execute polymorphism.

    I said (a long time ago):

...BUT the OP didn't ask about polymorphism and php doesn't support it at all anyway.

    Rob replied (also quite a long time ago):

Ummm, PHP supports polymorphism.. it has at least since PHP 4.

    http://whatis.techtarget.com/definition/0,,sid9_gci212803,00.html

1 and 3 in the above link are supported. Number 2 is not,

    however, that

    PHP supports 1 - but I have never heard of dynamic typing referred to as
    polymorphism.

    PHP doesn't support 2 - in so far as you can't define mabny
    functions with
    the same name (but different signatures) - this is usually referred
    to as
    overloading. - granted we have __call() on objects/classes which
    allows you
    to implement functionality that work like this.

is usually referred to as function/method overloading and not so

    often

by polymorphism. Number 3 is the most common type when discussing polymorphism.

    in php's case this comes down to the same thing as 1. - dynamic
    typing of
    variables.

    BUT there is a fourth form of polymorphism - one I would argue if the
    most common form when speaking about polymorphism with respect to
    programming,
    namely the ability to derive a subclass from more than one base
    class (simutaneously),
    this is something that php cannot do (thank <deity>).

Cheers, Rob.

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