<!DOCTYPE html>
<html lang="en">
 
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./js/jquery.min.js"></script>
</head>
 
<body>
    <div class="num">
        <div class="p-price">￥12.6</div>
        <div class="quantitu-form">
            <a href="javascript:;" class="decrement">-</a>
            <input type="text" class="itxt" value="1">
            <a href="javascript:;" class="crement">+</a>
        </div>
 
        <div class="p-sum">￥12.6</div>
    </div>
    <div class="num"></div>
    <div class="p-price">￥12.6</div>
    <div class="quantitu-form">
        <a href="javascript:;" class="decrement">-</a>
        <input type="text" class="itxt" value="1">
        <a href="javascript:;" class="crement">+</a>
    </div>
 
    <div class="p-sum">￥12.6</div>
 
    <div class="num">
        <div class="p-price">￥12.6</div>
        <div class="quantitu-form">
            <a href="javascript:;" class="decrement">-</a>
            <input type="text" class="itxt" value="1">
            <a href="javascript:;" class="crement">+</a>
        </div>
 
        <div class="p-sum">￥12.6</div>
    </div>
    <script>
        //点击加号 取的兄弟文本框的值
        $(function() {
            $(".crement").click(function() {
                //得到兄弟文本框的值
 
                var n = $(this).siblings(".itxt").val();
                n++;
                $(this).siblings(".itxt").val(n);
                //得到商品价格
                var p = $(this).parent().siblings(".p-price").html();
                //当前商品的价格
                p = p.substr(1);
                var p = $(this).parent().siblings(".p-sum").html("￥" + p * n);
 
            });
            $(".decrement").click(function() {
                //得到兄弟文本框的值
                var n = $(this).siblings(".itxt").val();
                if (n == 1) {
                    return false;
                }
 
 
                n--;
                $(this).siblings(".itxt").val(n);
                //得到商品价格
                var p = $(this).parent().siblings(".p-price").html();
                //当前商品的价格
                p = p.substr(1);
                var p = $(this).parent().siblings(".p-sum").html("￥" + p * n);
            });
 
        })
    </script>
</body>
 
</html>

运行结果

jquery购物车增减商品数量2-修改商品小计_javascript