問題描述

我正在用 PHP 處理購物車，但似乎在各種地方都收到此錯誤注意:未定義索引:".錯誤是指不同地方編碼的相似位.例如，我有一段代碼可以計算用戶決定訂閱的月份的套餐價格.我有以下錯誤所指的變量:

I am working on a shopping cart in PHP and I seem to be getting this error "Notice: Undefined index:" in all sorts of places. The error refers to the similar bit of coding in different places. For example I have a piece of coding that calculates a package price with the months a user decides to subscribe. I have the following variables where the errors refers to:

    $month = $_POST['month'];
    $op = $_POST['op'];

$month 變量是用戶在表單中輸入的數字，$op 變量是不同的包，其值存儲在用戶從表單上的單選按鈕中選擇的變量中.

The $month variable is the number the user inputs in a form, and the $op variable is different packages whose value are stored in a vriable that a user selects from radio buttons on the form.

我希望這在某種程度上是清楚的.

I hope that is clear in some way.

謝謝

抱歉忘了提到當用戶提交數據時它們會消失.但是當他們第一次來到頁面時，它會顯示這個錯誤.我怎樣才能擺脫它而不顯示它?

Sorry forgot to mention that they do go away when the user submits the data. But when they first come to the page it displays this error. How I can get rid of it so it doesnt display it?

--

這是代碼:

<?php
    $pack_1 = 3;
    $pack_2 = 6;
    $pack_3 = 9;
    $pack_4 = 12;
    $month = $_POST['month'];
    $op = $_POST['op'];
    $action = $_GET['action'];

    if ( $op == "Adopter" ) {
       $answer = $pack_1 * $month;
    }

    if ( $op == "Defender" ) {
      $answer = $pack_2 * $month;
    }

    if ( $op == "Protector" ) {
      $answer = $pack_3 * $month;
    }

    if ( $op == "Guardian" ) {
      $answer = $pack_4 * $month;
    }

    switch($action) {   
        case "adds":
            $_SESSION['cart'][$answer][$op];
            break;
    }
?>  

推薦答案

您正試圖訪問未設置的數組中的索引.這會引發通知.

You're attempting to access indicies within an array which are not set. This raises a notice.

很可能您現在已經注意到它，因為您的代碼已移至 php.ini 將 error_reporting 設置為包含 E_NOTICE 的服務器.通過將 error_reporting 設置為 E_ALL & 來抑制通知~E_NOTICE(不推薦)，或者在嘗試訪問之前驗證索引是否存在:

Mostly likely you're noticing it now because your code has moved to a server where php.ini has error_reporting set to include E_NOTICE. Either suppress notices by setting error_reporting to E_ALL & ~E_NOTICE (not recommended), or verify that the index exists before you attempt to access it:

$month = array_key_exists('month', $_POST) ? $_POST['month'] : null;

這篇關于PHP 錯誤:注意:未定義索引:的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！