从 jquery 购物车中获取余额

Question

我输入amount作为输入：<input style="width:200px" type="number" value="amount" class="form-control pull-right prc" placeholder="Enter amount">我script的是：   $('.form-group').on('input', '.prc', function(){    var totalSum = 0;    var currbalance = 0;    $('.form-group .prc').each(function(){        var quantity = $(this).val();        var price=$(this).attr('price');        var item_amount= parseFloat(price*quantity);        if ($.isNumeric(quantity)){            totalSum += parseFloat(item_amount);        }        var amount=$(this).attr('amount');        if ($.isNumeric(amount)){            currbalance = amount - totalSum;        }    });    $('#total_price').text('RM '+totalSum.toFixed(2));    $('#balance').text('RM '+currbalance.toFixed(2));});我想使用balanceid 显示它： <p>Balance: <b id="balance">RM 0.00</b></p>但是我的输出没有显示。我觉得我value=amount的错了。

Answer 1

我已将data-amountand添加data-price到您的输入中，然后更改currbalance = amount - totalSum;为currbalance += (amount - totalSum);，因为如果不是currbalance，则不等于data-amount




$('.form-group').on('input', '.prc', function() {

  var totalSum = 0;

  var currbalance = 0;

  $('.form-group .prc').each(function() {

    var quantity = $(this).val();

    var price = $(this).attr('data-price');

    var item_amount = parseFloat(price * quantity);

    if ($.isNumeric(quantity)) {

      totalSum += parseFloat(item_amount);

    }

    var amount = $(this).attr('data-amount');

    if ($.isNumeric(amount)) {

      currbalance += (amount - totalSum);

    }

  });

  $('#total_price').text('RM ' + totalSum.toFixed(2));

  $('#balance').text('RM ' + currbalance.toFixed(2));

});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<div class="form-group">

  <input style="width:200px" type="number" data-amount="120" data-price="12" class="form-control pull-right prc" placeholder="Enter amount">

  <input style="width:200px" type="number" data-amount="220" data-price="22" class="form-control pull-right prc" placeholder="Enter amount">

</div>

<p>Total: <b id="total_price">RM 0.00</b></p>

<p>Balance: <b id="balance">RM 0.00</b></p>