Question

以下是使用单选按钮，文本框和下拉列表验证表单的代码。用于验证单选按钮和文本框的javascript工作正常。但下拉列表的JavaScript不起作用。你能告诉我，我做错了什么吗？

请帮忙！

提前致谢。

 <!DOCTYPE html>

<html>

<head>
<script type="text/javascript">


function validateForm()
{
var checked = null;
var name1 = document.forms["information"]["firstname"].value;
var n=name1.split(" ");
var name = n[0];
var sex = document.forms["information"]["sex"];
var e = document.getElementById("prof1");
var strUser = e.options[e.selectedIndex].value;
var strUser1 = e.options[e.selectedIndex].text;

  if(name == null || name== "")
{
alert('Enter First Name');
    return false;
}
for (var i=0;i<2;i++)
 {
if(sex[i].checked)
{
checked = sex[i];
return true;
}

 }
if (checked == null)
{
alert(' Enter Sex');
return false;
}


if(strUser==0)
{
alert("Enter Profession");
return false;
}   

}


</script>
</head>


<body>

<form name="information" onsubmit="return validateForm()" method="post"> 

    <text style="color:red">*</text> First Name: <input type="text"   name="firstname"><br><br>

                     Last Name: <input type="text" name="lastname"><br><br>



        <text style="color:red">*</text> Sex: <input type="radio" name="sex" value="Male"> Male
                          <input type="radio" name="sex"   value="Female"> Female <br><br>



        <text style="color:red">*</text> Profession: 

    <select id="prof1">
    <option value="0"> Select </option>
    <option value="1"> Engineer </option>
        <option value="2"> Doctor </option>
    <option value= "3"> Lawyer </option>
    <option value="4"> Others </option>
    </select>

    <input type="submit" value="Submit" />
    </form>             






</body>

</html>

Answer 1

if(sex[i].checked)
{
checked = sex[i];
return true;
}

Remove return true above.

Answer 2

for ( var i = 0; i < 2; i++) {
    if (sex[i].checked) {
        checked = sex[i];
        //return true;
    }

}

取消注释return true;

循环内的return语句返回值，这导致在执行此return语句后写入的代码不执行。

2

   if(strUser==0)

替换为

   if(strUser=="0")

原因：

http://www.w3schools.com/jsref/prop_select_selectedindex.asp

http://www.w3schools.com/jsref/prop_option_value.asp

下拉列表的验证不起作用

2 个答案: