當用戶提交時更新總價格陣列

Question

我有一個像下面一樣的嵌套數組。

cart ( 
[total] => 98 
[itemcount] => 3 
[items] => Array ([0] => 0 [1] => 3 [2] => 5) 
[itemprices] => Array ([0] => 33.00 [3] => 32.00 [5] => 33) 
[itemqtys] => Array ([0] => 1 [3] => 1 [5] => 1) 
[iteminfo] => Array ([0] => Chemistry [3] => Additional Mathematics [5] => Physics) 
) 

而且我在當用戶輸入正確的優惠碼開關下面的代碼，此功能將被觸發。我可以讓它工作來顯示折扣價格。

$anewvalue = 16.50; 
$physubject = "Physics"; 
$index = array_search($physubject , $cart->iteminfo); 
if (false !== $index) { 
$cart->itemprices[$index] = $anewvalue;} 

問題是，我該如何更新總每當一個正確的折扣代碼的用戶密鑰並提交表單，從而使總價格將總是最新的，因爲現在沒有做到這一點。

Answer 1

您需要在每次應用正確的折扣時重新計算總計。

if (false !== $index) { 
    $cart->itemprices[$index] = $anewvalue; 
    //re-calculate the total 
    $total = 0; 
    foreach ($cart->itemprices as $key=>$itemprice) { 
     $total += $itemprice * $cart->itemqtys[$key]; 
    } 
    $cart->total = $total 
}