Php 从另一个类函数调用变量

我有一门课叫ot_lev_折扣

在该类中，我有一个函数：

    <?php
/*
<<<<<<< ot_lev_discount.php
  $Id: ot_lev_discount.php,v 1.0 2002/04/08 01:13:43 hpdl Exp $
=======
  $Id: ot_lev_discount.php,v 1.3 2002/09/04 22:49:11 wilt Exp $
  $Id: ot_lev_discount.php,v 2.4 2006/02/28 12:10:01 maniac101 Exp $
modified to calc discount correctly when tax is included in discount
>>>>>>> 2.4

  osCommerce, Open Source E-Commerce Solutions
  http://www.oscommerce.com

  Copyright (c) 2002 osCommerce

  Released under the GNU General Public License
*/

  class ot_lev_discount {
    var $title, $output;

    function ot_lev_discount() {
      $this->code = 'ot_lev_discount';
      $this->title = MODULE_LEV_DISCOUNT_TITLE;
      $this->description = MODULE_LEV_DISCOUNT_DESCRIPTION;
      $this->enabled = MODULE_LEV_DISCOUNT_STATUS;
      $this->sort_order = MODULE_LEV_DISCOUNT_SORT_ORDER;
      $this->include_shipping = MODULE_LEV_DISCOUNT_INC_SHIPPING;
      $this->include_tax = MODULE_LEV_DISCOUNT_INC_TAX;
      $this->calculate_tax = MODULE_LEV_DISCOUNT_CALC_TAX;
      $this->table = MODULE_LEV_DISCOUNT_TABLE;
//      $this->credit_class = true;
      $this->output = array();
    }

    function process() {
      global $order, $ot_subtotal, $currencies;
      $od_amount = $this->calculate_credit($this->get_order_total());
      if ($od_amount>0) {
      $this->deduction = $od_amount;
      $this->output[] = array('title' => $this->title . ':',
                              'text' => '<b>' . $currencies->format($od_amount) . '</b>',
                              'value' => $od_amount);
    $order->info['total'] = $order->info['total'] - $od_amount;
    if ($this->sort_order < $ot_subtotal->sort_order) {
      $order->info['subtotal'] = $order->info['subtotal'] - $od_amount;
    }
}
    }


  function calculate_credit($amount) {
    global $order;
    $od_amount=0;
    $table_cost = split("[:,]" , MODULE_LEV_DISCOUNT_TABLE);
    for ($i = 0; $i < count($table_cost); $i+=2) {
          if ($amount >= $table_cost[$i]) {
            $od_pc = $table_cost[$i+1];
          }
        }
// Calculate tax reduction if necessary
    if($this->calculate_tax == 'true') {
// Calculate main tax reduction
      $tod_amount = round($order->info['tax']*10)/10*$od_pc/100;
      $order->info['tax'] = $order->info['tax'] - $tod_amount;
// Calculate tax group deductions
      reset($order->info['tax_groups']);
      while (list($key, $value) = each($order->info['tax_groups'])) {
        $god_amount = round($value*10)/10*$od_pc/100;
        $order->info['tax_groups'][$key] = $order->info['tax_groups'][$key] - $god_amount;
      }  
    }


   $od_amount = $od_pc;
   // if you want to use %age instead of flat amount:  $od_amount = round($amount*10)/10*$od_pc/100;


//    $od_amount = $od_amount + $tod_amount;
// maniac101 above line was adding tax back into discount incorrectly for me
    return $od_amount;
  }


  function get_order_total() {
    global  $order, $cart;
    $order_total = $order->info['total'];
// Check if gift voucher is in cart and adjust total
    $products = $cart->get_products();
    for ($i=0; $i<sizeof($products); $i++) {
      $t_prid = tep_get_prid($products[$i]['id']);
      $gv_query = tep_db_query("select products_price, products_tax_class_id, products_model from " . TABLE_PRODUCTS . " where products_id = '" . $t_prid . "'");
      $gv_result = tep_db_fetch_array($gv_query);
      if (ereg('^GIFT', addslashes($gv_result['products_model']))) { 
        $qty = $cart->get_quantity($t_prid);
        $products_tax = tep_get_tax_rate($gv_result['products_tax_class_id']);
        if ($this->include_tax =='false') {
           $gv_amount = $gv_result['products_price'] * $qty;
        } else {
          $gv_amount = ($gv_result['products_price'] + tep_calculate_tax($gv_result['products_price'],$products_tax)) * $qty;
        }
        $order_total=$order_total - $gv_amount;
      }
    }
    if ($this->include_tax == 'false') $order_total=$order_total-$order->info['tax'];
    if ($this->include_shipping == 'false') $order_total=$order_total-$order->info['shipping_cost'];
    return $order_total;
  }   



    function check() {
      if (!isset($this->check)) {
        $check_query = tep_db_query("select configuration_value from " . TABLE_CONFIGURATION . " where configuration_key = 'MODULE_LEV_DISCOUNT_STATUS'");
        $this->check = tep_db_num_rows($check_query);
      }

      return $this->check;
    }

    function keys() {
      return array('MODULE_LEV_DISCOUNT_STATUS', 'MODULE_LEV_DISCOUNT_SORT_ORDER','MODULE_LEV_DISCOUNT_TABLE', 'MODULE_LEV_DISCOUNT_INC_SHIPPING', 'MODULE_LEV_DISCOUNT_INC_TAX','MODULE_LEV_DISCOUNT_CALC_TAX');
    }

    function install() {
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) values ('Display Total', 'MODULE_LEV_DISCOUNT_STATUS', 'true', 'Do you want to enable the Order Discount?', '6', '1','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, date_added) values ('Sort Order', 'MODULE_LEV_DISCOUNT_SORT_ORDER', '999', 'Sort order of display.', '6', '2', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Include Shipping', 'MODULE_LEV_DISCOUNT_INC_SHIPPING', 'true', 'Include Shipping in calculation', '6', '3', 'tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Include Tax', 'MODULE_LEV_DISCOUNT_INC_TAX', 'true', 'Include Tax in calculation.', '6', '4','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function ,date_added) values ('Calculate Tax', 'MODULE_LEV_DISCOUNT_CALC_TAX', 'false', 'Re-calculate Tax on discounted amount.', '6', '5','tep_cfg_select_option(array(\'true\', \'false\'), ', now())");
      tep_db_query("insert into " . TABLE_CONFIGURATION . " (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, date_added) values ('Discount Percentage', 'MODULE_LEV_DISCOUNT_TABLE', '100:7.5,250:10,500:12.5,1000:15', 'Set the price breaks and discount percentages', '6', '6', now())");
    }

    function remove() {
      $keys = '';
      $keys_array = $this->keys();
      for ($i=0; $i<sizeof($keys_array); $i++) {
        $keys .= "'" . $keys_array[$i] . "',";
      }
      $keys = substr($keys, 0, -1);

      tep_db_query("delete from " . TABLE_CONFIGURATION . " where configuration_key in (" . $keys . ")");
    }

  }
?>

---

我似乎能够以这种方式调用类全局变量，但不能调用类函数中的变量

global

不会使变量成为类的属性，它只告诉您该值可以在它的任何方法中使用

---

您可以通过调用

$ot_lev_discount->od_amount

来解决此问题，请参见，您正在尝试获取类的

od_amount

属性，但您的类没有

您需要像这样修改类：

class ot_lev_discount  {

    ...

    public $od_amount;

    function calculate_credit($amount)
    {
         ...
         $this->od_amount = $od_amount;

         return $od_amount;
    }

}

通过这种方式，您将能够使用

$ot\u lev\u折扣->od\u金额

访问该物业。当然，除非调用

$ot\u lev\u discount->calculate\u credit（）

函数，否则其值将为空

---

花些时间阅读关于类、对象、它们的属性和变量范围的文档。它应该可以帮助您了解所面临的问题（这些是面向对象编程的一般主题，而不仅仅是PHP）。

函数中的变量具有该函数的局部范围，不能从函数外部调用。您可以通过执行以下操作使这些变量的作用域类级别和公共级别：

class ot_lev_discount {
    public $od_amount;
    ....
}

然后您可以按如下方式访问变量：

$var = new ot_lev_discount();
$var->od_amount;

尽管在本例中，每次创建新对象时，该对象都会有自己的od_amount变量，该变量与同一类的另一个对象不同，除非对其执行相同的计算，否则不会有相同的值

---

或者，调用函数并获取返回值。

构造函数中有什么？那么，

$ot\u lev\u折扣->od\u金额

返回什么？

$od\u amount

是否为

ot\u lev\u折扣的属性

？如果你发布了更多（全部）类的话会有所帮助；与普通函数中的局部变量作用于该函数的方式完全相同。。。。你为什么不这么想？我把整个班级都加进去看看$ot_lev_折扣->od_金额不返回任何内容。至少当我像现在这样回应的时候没有？我不知道你说的是什么意思，它是奥托列夫的财产吗_discount@MarkBaker我对oop还很陌生，所以我一直在想办法。真的，试着删除所有那些

global

需要的函数参数，设置类属性和正确的返回

Globals

像这样毫无疑问是邪恶的（他们有时间和地点，不是这样）。好吧，我试着公开$od\u amount，但我得到了一个t\u public解析错误。我将尝试调用该函数并获取返回值，但我不太确定如何执行该操作，因为它需要$amount，否则我将得到“missing argument”错误您必须在函数外部但在类内部声明属性。您不能在函数内部设置

public

属性。我也尝试过这样做，但当我从第二个类回显它时，它没有数量。。因此，它需要与您的替代建议一起完成，我认为这样可以计算出金额，然后我在返回$od_金额时，我想回应这一点。。我就是不知道怎么做，就像我说的——同一个类的两个对象不是同一个变量，在它们的作用域内，变量的值会不同$var1=新的od水平折扣（）$var2=新的od水平折扣$var1->od_金额=3；//$var2->od\U金额仍然为空。如果希望在类的所有实例之间保持值的静态，也可以查找单例类。因此，我尝试从calculate_credit函数中获取具有相同值的变量。我是否需要生成一个返回该值的get函数？我有点迷路了。

$var = new ot_lev_discount();
$var->od_amount;