从类OOPS的外部获取私有变量的最后一个值

Question

我有一个核心类，但我不能修改核心类。我的核心类代码如下所示

class Test
{
    private $container = [];
    public function sample($input)
    {
            return array_push($this->container, $input);
    }
}

class Size extends Test
{  
  private $maxSize = 10;
  public function sizeadd($element)
  {
      //I want get the parent container 
        return parent::sample($element);
  }
}

$sizeval = new Size(); 
$sizeval->sizeadd('1');
$sizeval->sizeadd('2');

已成功添加值。但我的问题是，我只想添加10个值，所以我想要来自父类的count($this->container)。然后，我想检查sizeadd函数，如下所示

public function sizeadd($element)
      {
          if(count(container count)< $this->maxSize)
            return parent::sample($element);
      }

我无法获取父类$container array。

Answer 1

尝试更改扩展类，如下所示：

class Size extends Test
{

    private $maxSize = 10;

    /**
     * To track how many elements are being added
     * 
     * @var integer
     */
    private static $count = 0;

    /**
     * Adding element in size
     * 
     * @param integer $element
     * @return integer
     */
    public function sizeadd($element)
    {
        if (self::$count < $this->maxSize) {
            self::$count = self::$count + 1;
            return parent::sample($element);
        }
    }

    /**
     * This is just for getting the current number of count
     * this is optional method.
     * @return integer
     */
    public function getCount() 
    {
        return self::$count;
    }
}

Answer 2

在基类中创建一个函数来计算容器数量，并在子类中使用该函数来获取容器的总数量。

class Test
{
    private $container = [];
    public function sample($input)
    {
            return array_push($this->container, $input);
    }
    // counts container
    public function countContainer(){
         return count($this->container);
    }
}