Question

我希望有人选择一个选项，但不是第一个选项-- Select --.

HTML

<select name = "sources" id = "brandname" required onblur = "selectText()" />
     <option value = "select"> -- Select -- </option>
     <option value = "referal"> Referal </option>
     <option value = "justdial"> Justdial </option>
     <option value = "sulekha"> Sulekha </option>
     <option value = "website"> Website </option>
     <option value = "others"> Others </option>
</select>

JS

if (document.getElementById("brandname").value == "select") {
    alert("Please select the required value");
    document.getElementById("brandname")[1].focus();
}

它执行警报消息，之后它移动到下一个字段。但它应该坚持下拉，直到并且除非选择值改变为任何其他值。

代码有什么问题？提前谢谢！

Answer 1

<强> HTML

<select id="mySelect">
    <option>v1</option>
    <option>v2</option>
    ...
</select>

<强>的JavaScript

var s = document.getElementById("mySelect");

使用

检查所选值

s.options[s.selectedIndex].value // Keep this in mind

如果声明：

if(s.options[s.selectedIndex].value == "select") {
    alert("A value is required!");
    s.focus(); 
}

（没有[1]的焦点：

document.getElementById("brandname").focus();

）

Demo

Answer 2

只需从焦点声明中删除[1]。由于getElementById 始终会返回单个对象。

var selectText =function(){
if(document.getElementById("brandname").value == "select") {
            alert("Please select the required value");
            document.getElementById("brandname").focus();
        }}

<select name = "sources" id = "brandname" required onblur = "selectText()" />
     <option value = "select"> -- Select -- </option>
     <option value = "referal"> Referal </option>
     <option value = "justdial"> Justdial </option>
     <option value = "sulekha"> Sulekha </option>
     <option value = "website"> Website </option>
     <option value = "others"> Others </option>
</select>

下拉验证，焦点方法不起作用

2 个答案: