更改子類中的屬性php

Question

我想創建不同的類，只有一個變量具有不同的值，其他所有元素都應該與父類相同。

這裏是父類

class parentClass { 

    private $param_name_saved = 'files'; 

     protected $image_objects = array(); 

     function __construct($options = null, $initialize = true, $error_messages = null) { 
      $this->options = array(
       'script_url' => $this->get_full_url().'/', 
       'upload_dir' => dirname($this->get_server_var('SCRIPT_FILENAME')).'/files/2', 
       'upload_url' => $this->get_full_url().'/files/2', 
       'user_dirs' => false, 
       'mkdir_mode' => 0755, 
       'param_name' => $this->param_name_saved, 
       'tost' => 'files', 
       // Set the following option to 'POST', if your server does not support 
       // DELETE requests. This is a parameter sent to the client: 
       'delete_type' => 'DELETE', 
       'access_control_allow_origin' => '*', 
       'access_control_allow_credentials' => false, 
       'access_control_allow_methods' => array(
        'OPTIONS', 
        'HEAD', 
        'GET', 
        'POST', 
        'PUT', 
        'PATCH', 
        'DELETE' 
       ) 
    } 
} 

我想與財產$不同的價值創造少兒班param_name_saved

這是我想創造

class childClassone extends parentClass { 
     private $param_name_saved = 'files3'; 
} 

class childClasstwo extends parentClass { 
     private $param_name_saved = 'files2'; 
} 

當我用什麼上面的代碼不是我在這裏做錯了什麼？

Answer 1

你必須改變幾件事情：

1. 將parentClass::$param_name_saved的可見性更改爲受保護。
2. 更新子類的構造函數。

所以：

class parentClass 
{ 
    protected $param_name_saved = 'files'; 
    // ... 
} 

class childClassone extends parentClass 
{ 
    function __construct($options = null, $initialize = true, $error_messages = null) 
    { 
     $this->param_name_saved = 'files3'; 
     parent::__construct($options, $initialize, $error_messages); 
    } 
} 

Answer 2

私有屬性對於子類不可見。

您既可以可見性改變，以保護，或添加setParamNameSaved父類的函數，調用子類中此功能更改的屬性param_name_saved