Building on classes -- inheritance help needed

[mountain.dog@gmail.com]

Hi There,
I'm trying to understand inheriting properties object and I'm not
fully understanding the ways to accomplish this.

For example, I have a PHP array that is generate in "class a". I
would like to use this array with its values in "class b". When I
create a new instance of "class b" I get the array but none of the
values are present. Make sense? An explanation on how to accomplish
this would be great. A simplified example is below. Any help /
guidance would be greatly welcome. -- CH

class a {
public $one;

public function someMethod() {
$one = array("1");
}
}

class b extends class a {
public $one;
public $two

function someOtherMethod () {
print_r($this->one);
}
}

$display = new a;
$displayb = new b($a);
$displayb->someOtherMetho d();

//outputs
Array ( [0] =)

[Toby A Inkster]

Re: Building on classes -- inheritance help needed

mountain.dog wrote:

$display = new a;
$displayb = new b($a);
$displayb->someOtherMetho d();

You're misunderstandin g what inheritance is; so the second line of the
above excerpt doesn't do what you think it does. Replace those three
lines with:

$displayb = new b();
$displayb->someMethod() ;
$displayb->someOtherMetho d();

--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~ http://tobyinkster.co.uk/contact
Geek of ~ HTML/SQL/Perl/PHP/Python*/Apache/Linux

* = I'm getting there!

[Jerry Stuckle]

Re: Building on classes -- inheritance help needed

mountain.dog@gm ail.com wrote:

Hi There,
I'm trying to understand inheriting properties object and I'm not
fully understanding the ways to accomplish this.
>
For example, I have a PHP array that is generate in "class a". I
would like to use this array with its values in "class b". When I
create a new instance of "class b" I get the array but none of the
values are present. Make sense? An explanation on how to accomplish
this would be great. A simplified example is below. Any help /
guidance would be greatly welcome. -- CH
>
class a {
public $one;
>
public function someMethod() {
$one = array("1");
}
}
>
class b extends class a {
public $one;
public $two
>
function someOtherMethod () {
print_r($this->one);
}
}
>
$display = new a;
$displayb = new b($a);
$displayb->someOtherMetho d();
>
//outputs
Array ( [0] =)
>

Two problems.

First of all, $one in class 'b' overrides $one in class 'a'. So you end
up with two variables named $one - one in 'a' and one in 'b'.

Secondly, you don't need

$display = new a;

When you create an instance if 'b' you automatically get an instance of
'a'. 'a' is part of 'b's implementation.


--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attgl obal.net
=============== ===

[mountain.dog@gmail.com]

Re: Building on classes -- inheritance help needed

Thank you Toby. Your brief example helped clarify a lot. I appreciate
your help. One question - what's the difference between these two
instances?
$displayb = new b();
versus
$displayb = new b;
thanks!

On Mar 21, 11:27 am, Toby A Inkster <usenet200...@t obyinkster.co.u k>
wrote:

mountain.dog wrote:

$display = new a;
$displayb = new b($a);
$displayb->someOtherMetho d();

>
You're misunderstandin g what inheritance is; so the second line of the
above excerpt doesn't do what you think it does. Replace those three
lines with:
>
$displayb = new b();
$displayb->someMethod() ;
$displayb->someOtherMetho d();
>
--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~http://tobyinkster.co.uk/contact
Geek of ~ HTML/SQL/Perl/PHP/Python*/Apache/Linux
>
* = I'm getting there!

[Toby A Inkster]

Re: Building on classes -- inheritance help needed

mountain.dog@gm ail.com wrote:

One question - what's the difference between these two
instances?
$displayb = new b();
versus
$displayb = new b;

In this case, no difference.

You can however, write a class with a constructor function which takes one
or more arguments, in which case the brackets are required:

$displayb = new b('something', 123, 456);

--
Toby A Inkster BSc (Hons) ARCS
Contact Me ~ http://tobyinkster.co.uk/contact
Geek of ~ HTML/SQL/Perl/PHP/Python*/Apache/Linux

* = I'm getting there!