Question

我已经搞砸了好几天了，无法解决这个问题。我是新手，其他人试图帮助我，但它不起作用。我基本上尝试制作一个下拉菜单表单，当用户点击下拉列表中的某个项目时，下拉或下面的文本会显示“您已点击此内容”或我想要的任何内容，例如“你选择这个已经节省了10％！“

有人可以帮忙吗？我目前的代码是这样的：

<form>
<p align="center"><b>Select a Payment:</b>
<select id="setit" onchange="javascript:showRelatedValue(this.value)">
<option value="">Select one</option>
    <option value="">1 Month: $4.99</option>
    <option value="">3 Months: $14.99</option>
    <option value="">6 Months: $29.99</option></select>
<br />
<br />
     <input type="button" value="Add to Cart"
onclick="window.open(setit.options[setit.selectedIndex].value)">
</p>
</form>
<script>
     function showRelatedValue(String value)
     {
         if(value==1 Month: $4.99)
         alert("You have selected One Month");
         if(value==3 Months: $14.99)
         alert("You have selected Three Months");
         if(value==6 Months: $29.99)
         alert("You have selected Six Months");
     }
</script>

或者有更好的方法吗？谢谢你的时间。

Answer 1

试试这个 - DEMO

<form>
<p align="center"><b>Select a Payment:</b>
<select id="setit" onchange="javascript:showRelatedValue(this.value)">
<option value="">Select one</option>
    <option value="1">1 Month: $4.99</option>
    <option value="3">3 Months: $14.99</option>
    <option value="6">6 Months: $29.99</option></select>
<br />
<br />
     <input type="button" value="Add to Cart"
onclick="window.open(setit.options[setit.selectedIndex].value)">
</p>
</form>
<script>
     function showRelatedValue(value)
     {
         if(value==1)
         alert("You have selected One Month");
         if(value==3)
         alert("You have selected Three Months");
         if(value==6)
         alert("You have selected Six Months");
     }
</script>

Answer 2

将值保存在您的选项中..否则您必须与完整文本进行比较..

<form>
<p align="center"><b>Select a Payment:</b>
<select id="setit" onchange="javascript:showRelatedValue(this.value)">
<option value="">Select one</option>
    <option value="4.99">1 Month: $4.99</option>
    <option value="14.99">3 Months: $14.99</option>
    <option value="29.99">6 Months: $29.99</option></select>
<br />
<br />
     <input type="button" value="Add to Cart"
onclick="window.open(setit.options[setit.selectedIndex].value)">
</p>
</form>

<script>
     function showRelatedValue(value)
     {
         if(value== '4.99')
         alert("You have selected One Month");
         if(value== '14.99')
         alert("You have selected Three Months");
         if(value== '29.99')
         alert("You have selected Six Months");
     }
</script>

Answer 3

您不必指定参数的数据类型

 function showRelatedValue(value)
 {
     if(value == '1')
        alert("You have selected One Month");
     else if(value == '3')
        alert("You have selected Three Months");
     else if(value == '6')
        alert("You have selected Six Months");
 }

也无需在onchange事件onchange="showRelatedValue(this.value)"

中添加javascript

用户在下拉菜单中选择项目后显示的文字？

3 个答案: