我的工作是将以下javascript函数转换为PHP并显示正确的结果。如何使用PHP乘以NumA和NumB选择选项的两个值？折扣必须显示在折扣输入框中，以及总输入框中的总计。我在创建一个PHP脚本时遇到困难，该脚本获取两个选定选项的值并将它们相乘，同时在下面的框中显示两个结果。
这是包含我需要转换为PHP的函数的HTML代码。
<!DOCTYPE html>
<html>
<head>
<title>
</title>
<script>
var numA = 0;
function totalA(valA) {
if (valA) {
numA = Number(valA);}
var disc = numB*numA;
var totalCost = (numA - disc);
document.getElementById("total").value = "$" + totalCost.toFixed(2);
document.getElementById("discount").value = "$" + disc.toFixed(2);}
var numB = 0;
function totalB(valB) {
if (valB) {
numB = Number(valB);}
var disc = numB*numA;
var totalCost = (numA - disc);
document.getElementById("total").value = "$" + totalCost.toFixed(2);
document.getElementById("discount").value = "$" + disc.toFixed(2);}
</script>
</head>
<div align="center">
<br>
<form name id="Main">
<select id="numA" placeholder="Please select a service" onchange="totalA(this.value);">
<option value="" disabled selected>Select your service</option>
<option value="125">Makeover</option>
<option value="60">Hair Styling</option>
<option value="35">Manicure</option>
<option value="200">Permanent Makeup</option>
</select>
<br><br>
<select id="NumB" placeholder="Please select the discount" onchange="totalB(this.value);">
<option value="" disabled selected>Select the discount</option>
<option value="0">0%</option>
<option value=".1">10%</option>
<option value=".2">20%</option>
</select>
<br><br>
<td>Discount Coupon: <input id="discount" name="showTotal" type="text" value="$0.00" size="10" readonly/></td>
<td>Grand Total: <input id="total" name="showTotal" type="text" value="$0.00" size="10" readonly=""/></td>
<br><br>
</form>
<hr>
</div>
</html>
答案 0 :(得分：1)
首先更新您的表单：
<form action="" method="post">
<select name="service" id="service" placeholder="Please select a service">
<option value="" disabled selected>Select your service</option>
<option value="125">Makeover</option>
<option value="60">Hair Styling</option>
<option value="35">Manicure</option>
<option value="200">Permanent Makeup</option>
</select>
<br><br>
<select name="discount" id="discount" placeholder="Please select the discount">
<option value="" disabled selected>Select the discount</option>
<option value="0">0%</option>
<option value=".1">10%</option>
<option value=".2">20%</option>
</select>
<br><br>
<button type="submit">Calculate</button>
</form>
使用PHP处理表单提交（计算总成本和折扣）：
<?php
$service = isset($_POST['service']) ? $_POST['service'] : 0;
$discount = isset($_POST['discount']) ? $_POST['discount'] : 0;
$total_discount = number_format($discount * $service, 2);
$total_cost = number_format($service - $total_discount, 2);
?>
最后，显示总费用＆amp;折扣：
<p>Discount Coupon: <input id="discount" type="text" value="$<?php echo $total_discount; ?>"/></p>
<p>Grand Total: <input id="total" type="text" value="$<?php echo $total_cost; ?>"/></p>