今天再看PHP手冊(cè)時(shí)候發(fā)現(xiàn)一個(gè)問(wèn)題，那就是PHP子類(lèi)對(duì)象不能直接訪問(wèn)父類(lèi)的屬性，這實(shí)在讓人疑惑，現(xiàn)在先記錄，以后看有什么解釋沒(méi)有。例子：

class MyClass

{

? ? public $public = 'Public';

? ? protected $protected = 'Protected';

? ? private $private = 'Private';

? ? function printHello()

? ? {

echo "This is Myclass".PHP_EOL;

? ? ? ? echo $this->public.PHP_EOL;

? ? ? ? echo $this->protected,PHP_EOL;

? ? ? ? echo $this->private,PHP_EOL;

? ? }

}

class MyClass2 extends MyClass

{

public $public = 'Publi2c';

? ? protected $protected = 'Protected2';

? ? function printHello2()

? ? {

? ? ? ? echo $this->public.PHP_EOL;

? ? ? ? echo $this->protected,PHP_EOL;

? ? ? ? echo parent::$public,PHP_EOL; //此時(shí)，會(huì)報(bào)錯(cuò)，Uncaught Error: Access to undeclared static property: MyClass::$public?

? ? }

}

$obj2 = new MyClass2();

$obj2->printHello2();