第九节--绑定

代码如下:

class Father
{
protected $salutation = "Hello there!"; //问候
public function getSalutation()
{
print("$this->salutation\n");
$this->identify();
}
protected function identify()
{
print("I am Father.
\n");
}
};
class Son extends Father
{
protected $salutation = "Hey!"; //父类中的protected $salutation 被覆写
protected function identify() //父类中的protected identify() 被覆写
{
print("I am Son.
\n");
}
};
$obj = new Son();
$obj->getSalutation(); //输出Hey! I am Son.
?>

代码如下:

class Father
{
private $salutation = "Hello there!";
public function getSalutation()
{
print("$this->salutation\n");
$this->identify();
}
private function identify()
{
print("I am Father.
\n");
}
}
class Son extends Father
{
private $salutation = "Hey!";
private function identify()
{
print("I am Son.
\n");
}
}
$obj = new Son();
$obj->getSalutation(); //输出Hello there! I am Father.
?>

代码如下:

class User //用户
{
protected function isAuthorized() //是否是验证用户
{
return(FALSE);
}
public function getName() //获得名字
{
return($this->name);
}
public function deleteUser($username) //删除用户
{
if(!$this->isAuthorized())
{
print("You are not authorized.
\n");
return(FALSE);
}
//delete the user
print("User deleted.
\n");
}
}
class AuthorizedUser extends User //认证用户
{
protected function isAuthorized() //覆写isAuthorized()
{
return(TRUE);
}
}
$user = new User;
$admin = new AuthorizedUser;
//not authorized
$user->deleteUser("Zeev");
//authorized
$admin->deleteUser("Zeev");
?>