我有这个代码
<script>
function select(val, item)
{
var prize = $(".prize"+item).val();
var prize = prize*val;
$(".dollar"+item).html(prize);
//----- THIS CODE ERROR --------//
$sub_total=$(".dollar1").val()+$(".dollar2").val()+$(".dollar3").val()+..... etc;
$(".total").html($sub_total);
// ---------------------------- //
}
</script>
<input type="hidden" value="140" class="prize1">
<select class="quantity" id="quant2" value="1" onchange="select(this.value, 1)"> src="1">
<option value="1" selected>1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
prize : <span class="dollar1" value="140">140</span>
<br>
<input type="hidden" class="prize2" value="150">
<select class="quantity" id="quant2" value="2" onchange="select(this.value, 2)"> src="2">
<option value="1">1</option>
<option value="2" selected>2</option>
<option value="3">3</option>
</select>
prize : <span class="dollar2" value="300">300</span>
...... etc
<br><br>
<label> TOTAL </label> : <span class="total">?????</span>
如何制作一个总元素，可以计算出价格上的所有金额吗？如果我在更改选择后如何，那么在dollar1 dollar2 dollar3 ... etc将总结，因为我在这个脚本上使用while()。我应该在这个脚本中做什么？
$sub_total=dollar1+dollar2+dollar3+..... etc;
$(".total").html($sub_total);
如果这个 php 代码
<?php
while($loll = $resultu->fetch_array(MYSQLI_BOTH)){
$id_item= $loll['id_item'];
$prize=$loll['prize'];
<input type="hidden" value="<?php echo $prize ?>" class="prize<?php echo $id_item ?> ">
<select class="quantity" value="<?php echo $id_item ?>" onchange="select(this.value, <?php echo $id_item ?>)"> src="<?php echo $id_item ?>">
<option value="1" selected>1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
prize : <span class="dollar<?php echo $id_item ?>" value="<?php echo $prize ?>"><?php echo $prize ?></span>
<br>
}
...... etc
<br><br>
<label> TOTAL </label> : <span class="total">?????</span>
我怎么能总结
$sub_total= ALL --> $(".dollar<?php echo $id_item ?>")?
下面是一个简单的 jQuery 示例，当用户更改选择元素时，它将运行总和计算：
.HTML
<select id="select1">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<select id="select2">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<input id="result" type="text"/>
JavaScript
$(document).ready(function () {
$('#select1, #select2').change(function () {
var num1 = Number($('#select1').val());
var num2 = Number($('#select2').val());
var sum = num1 + num2;
$('#result').val("$" + sum);
});
});