Just playing with PHP5 classes. Want to know: 1) Is this a good/bad way to use an abstract class? If bad, what's the optimal way to setup this code? 2) Is there any way to skip passing the variable $foo to the abstract class, yet allow the abstract class to have a constructor that does things?

1. foo.php

<p>Hello!</p>

<hr>

<?php

ini_set('display_errors', 1);
ini_set('log_errors', 1);
ini_set('error_log', dirname(__FILE__) . '/error_log.txt');
error_reporting(E_ALL);

include_once('class.child.php');
new Foo_Child();

?>

<hr>

<p>Goodbye.</p>

2. class.child.php

<?php

include_once('class.abstract.php');

class Foo_Child extends Foo_Abstact
{
	
	public function __construct() {
		
		$foo = 'this is foo';
		
		parent::__construct($foo);
		
		echo sprintf('<p>%s: %s</p>', __CLASS__, $foo);

		
	}
	
}

3. class.abstract.php

<?php

include_once('class.parent.php');

abstract class Foo_Abstact extends Foo_Parent
{
	
	public function __construct($foo) {
		
		parent::__construct($foo);
		
		echo sprintf('<p>%s: %s</p>', __CLASS__, $foo);
		
	}
	
}

4. class.parent.php

<?php

class Foo_Parent
{
	
	public function __construct($foo = 'nope') {
		
		echo sprintf('<p>%s: %s</p>', __CLASS__, $foo);
		
	}
	
}

5. output.md

Hello!

---

Foo_Parent: this is foo

Foo_Abstact: this is foo

Foo_Child: this is foo

---

Goodbye.

Discussion here.