Question

因此，我試圖在PHP中爲一個網站構建一個動態下拉列表，它來自我的數據庫中的一個類別數組，並且它正在工作，並且我得到了7個確切類型（7是我擁有的類別數量）。下面是代碼：

<?php 
$categories = getCategories(); 

$catList = '<select name="categoryId" id="categoryId">'; 
$catList .= '<option>Choose a Category</option>'; 

    foreach ($categories as $category){ 
    $catList .= "<option value='$category[categoryId]'"; 
     if(isset($categoryId)){ 
     if(category['categoryId'] === "$categoryId"){ 
      $catList .= ' selected '; 
     } 
     } 
    $catList .= ">$category[categoryName]</option>"; 
    } 
$catList .= "</select>"; 
?> 

，這裏是錯誤消息：

Notice: Use of undefined constant category - assumed 'category' in 
C:\my\path\to\the\addproduct.php on line 8 

Warning: Illegal string offset 'categoryId' in 
C:\my\path\to\the\addproduct.php on line 8 

作爲參考，8號線是if(category['categoryId'] === $categoryId){

Answer 1

你有8行錯字你忘記在類別前添加$。記住它是一個PHP變量。將其更改爲以下

if($category['categoryId'] === "$categoryId"){ 

Answer 2

變化

if(category['categoryId'] === "$categoryId"){ 

到

if($category['categoryId'] === "$categoryId"){