php - $new = new self($data);有私有(private)函数甚至变量oO？

Question

我的 php 5.3 有一个奇怪的行为

我有一个类在一个函数中加入了这个

       $new = new self($data);
        $new->setServiceManager($this->service);
        $new->cacheInstance();

但是函数 cacheInstance 是一个私有(private)函数....

private function cacheInstance()
    {
        foreach ($this->data as $name => $class) {...}
    }

有人可以解释一下为什么可以这样使用吗？这种方法不应该是私有(private)的，也就是从外部无法访问的吗？

更新:

好吧，现在我完全迷失了......我什至可以访问实例的私有(private)变量......就像什么......这必须是一些预期的行为，有人能给我指明方向吗？

Answer 1

如果您可以使用 new self() 创建类实例，则意味着您在该类中，当然您可以访问私有(private)属性和函数。此片段摘自 PHP 文档 (link)

/**
 * Define MyClass
 */
class MyClass
{
    public $public = 'Public';
    protected $protected = 'Protected';
    private $private = 'Private';

    function printHello()
    {
        echo $this->public;
        echo $this->protected;
        echo $this->private;
    }
}

$obj = new MyClass();
echo $obj->public; // Works
echo $obj->protected; // Fatal Error
echo $obj->private; // Fatal Error
$obj->printHello(); // Shows Public, Protected and Private

在你的情况下:

class Cache {
    private $service = null;

    private function cacheInstance()
    {
        foreach ($this->data as $name => $class) {}
    }

    public function setServiceManager( $service ) {

    }

    public function myTest( $data ) {
        $new = new self( $data );// you are in the class, so you can call new self()
        $new->setServiceManager($this->service);
        $new->cacheInstance();
    }
}
$cache = new Cache();
$cache->service; //Fatal error: Cannot access private property

$data = array();
$cache->myTest( $data );// working

$cache->cacheInstance();// not working