Question

我正在通过开发在线报价表来与我竞争。我试图根据是否勾选复选框来改变价格。

行为应该是：在初始页面加载 - 标准（从mysql - 变量）价格选中复选框时 - 广告$ 20（从mysql）到价格当未选中复选框时 - 返回标准变量价格

我现在的行为是：在初始页面加载 - 标准（从mysql - 变量）价格选中复选框时 - $ 20（来自mysql）但不添加原始价格当复选框未选中时 - NaN

我可以确认价格在mysql中存储为整数，例如292 任何帮助将不胜感激。

以下代码：在HTML页面中的PHP

<?php 
$table = $_GET['bintype'];
$pcode = $_GET['tags'];
include 'connect.php';
$result=mysqli_query($con,"SELECT * FROM $table WHERE short='$pcode'");
$row_cnt = mysqli_num_rows($result);
if($row_cnt == 0)
{
        PRINT "<p align='middle'>No go</p>"; 
 }
else
while($row=mysqli_fetch_array($result))
  {
  $b = number_format($row['barrow'], 2) AND "<div id='barrowid'>"; 
  $c = number_format($row['2m3 General'], 2) AND "<div id='total_price'>";
  $d = $row['2m3 General'] AND "<div id='total_number'>";

  echo "<form id='checkboxval'><input type='checkbox' id='checkit' name='menu1'
  value=".$b.">
  </input> <div id='total'>Total:$".$d."</div>
  </form>";
  }
mysqli_close($con);
?>

的javascript

var checkbox = document.getElementById("checkit");

checkbox.onclick = function () {
    var subtotalField = document.getElementById("total_price");
    var checkboxes = document.forms["checkboxval"].getElementsByTagName("input");
    var subtotal = document.getElementById("total_price");
    var total = document.getElementById("total_price");

 for (var i = 0, length = checkboxes.length; i < length; i++) {
    if (checkboxes[i].checked) {
        var newSubtotal = parseInt(subtotal.innerHTML) + parseInt(checkboxes[i].value);
        subtotal.innerHTML = newSubtotal; 
    }
}

    total = (parseFloat(subtotal));

    document.getElementById("total").innerHTML = "Total:$" + total;
};

Answer 1

您的变量subtotal和total是DOM元素 - 您需要在执行算术之前从中提取值。

for (var i = 0, length = checkboxes.length; i < length; i++) {
    if (checkboxes[i].checked) {
        var newSubtotal = parseInt(subtotal.innerHTML) + parseInt(checkboxes[i].value);
        subtotal.innerHTML = newSubtotal; 
    }
}

你的代码有点困惑。仔细查看它并删除冗余和重复的代码。另外，请检查：document.getElementById("$total_number");。带有id = "$total_number"的元素在哪里？

使用php使用javascript获取NaN值

1 个答案: