note 102905 deleted from language.oop5.visibility by danbrown
| From: | danbrown@php.net | Date: | Mon, 14 Mar 2011 15:05:12 +0000 |
| Subject: | note 102905 deleted from language.oop5.visibility by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-177854@lists.php.net to get a copy of this message | ||
Note Submitter: leoniu07 at gmail dot com
----
My 2 cents to "ryan dot m dot lange at gmail dot com"
<?php
class ParentClass
{
private $foo;
public function __construct()
{
$this->foo = 'foo';
}
public function foo()
{
echo $this->foo;
}
}
class ChildClass1 extends ParentClass
{
public function bar()
{
echo $this->foo;
}
}
class ChildClass2 extends ParentClass
{
public function __construct()
{
$this->foo = 'bar';
}
public function bar()
{
echo $this->foo;
}
}
$parent = new ParentClass();
$parent->foo(); // "foo"
$child1 = new ChildClass1();
$child1->foo(); // "foo"
$child1->bar(); // "Notice: Undefined property: ChildClass1::$foo in [file] on line
[line]"
//because, $child1 can't access private properties of the parent class and the variable
"foo" is not defined in it's own class either
$child2 = new ChildClass2();
$child2->foo(); // <nothing>, because there is a constructor defined in class ChildClass2,
the parent constructor won't be called. The private variable "foo" is not assigned a
value as a result and keeps null.
$child2->bar(); // "bar", because the variable "foo" has been defined and
assigned a value within class ChildClass2's constructor, "$this->foo =
'bar';". The variable "foo" only belongs to ChildClass2 and doesn't
override that "foo" in it's parent class.
?>
Hope my comments help.