当我尝试获取 JavaScript 数组的内容并将其值传递给 PHP 数组变量时遇到问题。
我正在做的是，当用户单击按钮时，单击的项目的值将添加到 javascript 数组中，每次 javascript 数组更新时，PHP 变量也会更新，因此内容显示 PHP 数组内容的 div。我没有使用表单来处理此事，而是使用按钮
但是，当我尝试使用 json_decode 函数获取 JavaScript 数组的值时，它给我一个 Message: undefined index: data 错误
我是 JavaScript、jQuery 和 AJAX 的初学者，所以请耐心等待
这是我的代码:
<script>
// ARRAY VARIABLE WHERE ITEM VALUES WILL BE STORED
var food_item = new Array();
// FUNCTION TO BE TRIGGERED WHEN USER CLICKED THE BUTTON, GET THE ITEM'S VALUE AND ADD IT TO ARRAY
function addToTray(data){
food_item.push(document.getElementById(data).value);
dataString = food_item; // array?
var jsonString = JSON.stringify(dataString);
$.ajax({
type: "POST",
url: "main",
data: {data: jsonString},
cache: false,
success: function(){
alert("OK");
}
});
}
</script>
<body>
...
// LINE OF CODE RESPONSIBLE FOR FETCHING JAVASCRIPT ARRAY VALUES
$this->session->userdata['food_tray'] = json_decode($_POST['data']);
// DIV TO BE UPDATED
<div class="col-md-3 food-tray" id="food-items" style="margin-top: 7%">
<!--FOOD TRAY-->
<div class="panel-heading">
<h3 class="ft-header">Food Tray</h3>
</div>
<div class="panel-body">
<?php
$count_fi = count($this->session->userdata('food_tray'));
echo "<p>Your Items (" . $count_fi . ")</p>";
if($count_fi == 0){
echo "<p class='no-avail-list'>NO ITEMS ADDED IN FOOD TRAY</p>";
}else{
echo "<table class='table borderless'>";
for($i = 0; $i < $count_fi; $i++){
echo "<tr>";
echo "<td>" . $this->session->userdata['food_tray'][$i] . "</td>";
echo "<td>P 200.00</td>";
echo "<td><form method='post'><input type='number' name='qty' min='1' max='100' value='1'/></form></td>";
echo "</tr>";
}
echo "</table>";
echo "<a href='' class='btn btn-success' data-toggle='modal' data-target='#myModal'>
Add Friend</a>";
echo "<a href='".base_url()."index.php/CheckOut' class='btn btn-warning'>Proceed to Checkout</a>";
}
?>
</div>
</div>
...
<?php
foreach($query->result() as $row){
echo "<div class='col-lg-7'>";
echo "<div class='thumbnail'>";
$file_name = strtolower(preg_replace('/[^A-Za-z0-9\-.]/', '', $row->name));
/*if(file_exists(FCPATH . '/assets/images/main/food/' . $file_name . '.jpg')){
echo "<img src='".base_url()."/assets/images/main/food/".$file_name.".jpg' alt='' width='320px' height='100px'>";
}else{
echo "<img src='http://placehold.it/320x150' alt=''>";
}*/
echo "<img src='http://placehold.it/320x150' alt=''>";
echo "<div class='caption'>";
echo "<h5 class='pull-right'>₱ " . $row->price . "</h5>";
echo "<h5><a href='#'>" . $row->name . "</a></h5>";
echo "<h5>Calorie Count : " . ($row->calorie_count == NULL ? "Not Available" : $row->calorie_count) . "</h5>";
// BUTTON FOR `addToTray()` FUNCTION
echo "<button class='btn btn-primary' id='".$row->id."' value='".$row->name."' style='width:100%' onclick='addToTray(".$row->id.")'>Add to Tray</button>";
// var_dump($row->name);
echo "</div>";
echo "</div>";
echo "</div>";
}
?>
</body>
谁知道如何解决这个问题？任何帮助，将不胜感激。
最佳答案
将您的 session 创建为
$array = array ('food_tray' => json_decode($javascriptarray));
$this->session->set_userdata($array);
检查您的 JavaScript 库是否已加载到“源”选项卡中。
关于javascript - json_decode 后未定义索引，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45725841/